From what I've seen, that type of cord cover costs significantly more than the various flexible tubings available; it could also be challenging to work with for someone that doesn't own much in the way of tools and isn't as versatile since it can only be run in straight lines and needs to be attached to a wall (which also makes it pretty immobile and therefore an impractical solution for any cord that gets moved around at all or plugged and unplugged regularly - for example our dehumidifier gets moved to different rooms sometimes).
That said, the cord covers Sindri uses have one MAJOR advantage over flexible tubing -
they're typically metal, making them truly chew-PROOF instead of just chew-resistant.
To choose the best option, the first thing you need to consider is how avid a chewer your bunn(s) are - if they generally leave cords alone and you simply want "just in case" protection, there's no reason to spend money on expensive metal cord covers when tubing will do the job just fine... however, if you've got a bunny who actively seeks out and destroys cords like they're on a mission, then tubing obviously won't be enough to thwart them. For bunnies who are casual to moderate cord chewers, the best (and most economical) way to go is probably to decide on a cord-by-cord basis which to use.
Some factors to consider:
~ cord location - is the cord in a place where you'd remember to check flex tubing frequently for signs of destruction? Is it in a room/area where the bunny typically has some degree of supervision (meaning you'd probably notice them chewing on the cord cover pretty quickly, as opposed to cords in a room where the bunn(s) are often alone)?
~ flexibility - is the cord one that you have to move often, that you routinely plug and unplug or is there any other reason why a wall-mounted, immovable cover would be particularly inconvenient?
~ expense and hassle of repairing or replacing the cord; whether what the cord powers is typically turned on - some cords are cheap and easily replaced, others (like appliance cords) could be extremely expensive to repair or replace. More importantly, if the cord is actively powering something, I imagine this raises the odds of your bunny getting hurt (possibly badly) if they manage to chew through the cord.
Another thing to consider is the thickness of the cord - if the bunny gets past flex tubing, a thick, well-insulated cord would stand up to more chewing before the bunny actually got to any the wires. Our dehumidifier has a TON of chew-marks in the cord because the bunnies were in our bedroom for a few hours and it was the one cord in the entire room that was unprotected (it was a recent addition and I completely forgot to put flex tubing on it ><), but thankfully the cord is so thick that they just dented the insulation all along the length without ever damaging the wires or, god forbid, themselves.
Basically, flex tubing or clear plastic tubing is great when you can get away with it... but depending on the cord and its location, there are times when it's probably better (and safer for your bunns) to shell out for the metal cord covers.
~~~~~
Finding a cheap but good tool to cut the metal covers:
(skip to the very bottom of this post if you just want the TLDR/trust my recommendation without wanting to know the details of how I picked what I did - it's in italics, so it's easy to spot. I promise, I know and love my tools... details are provided in case someone is actually interested in learning about tools and how to pick a good one.)
For obvious reasons, the metal covers are best cut with a good power tool. If you don't have power tools or want to buy one, a hand tool will still get the job done (it'll just be significantly more obnoxious). If you buy the cord covers at a hardware store and know what lengths you'll need, it *might* be possible to get them cut at the store (though many stores only cut lumber)... failing that, wander over to the power tool area (I say "power tool" because that section is traditionally easy as hell to spot) and find an employee - show them the covers and ask if they can recommend an inexpensive hand tool capable of cutting them. You should be able to get something like a handsaw or hacksaw capable of (eventually) cutting through metal for $7-10.
The cheapest power tool that can cut metal would be a rotary tool (ie Dremels and such), and rotary tools are pretty versatile so you'd almost certainly find more uses for it around the home. Some brands/models are priced as low as $20-40. I've got a
Dremel 4000, which is the most versatile model yet not the most expensive (it's around $100) - I love it to pieces and it's capable of most tasks around the home. It can sand (small areas), drill, cut plastic/metal/wood, carve/engrave and so much more... though it can't necessarily cut very thick things and is much more limited in its drilling abilities than a true drill.
Obviously, you don't want to shell out $100 unless you're really into your power tools, though, so time to discuss cheaper alternatives! Here are some tips on picking out a rotary tool:
~ Speed: variable speed is the sh*t, since you can fine-tune it to your precise wants and needs depending on what you're doing. However, many inexpensive rotary tools don't come with this option. My Dremel ranges from 5,000-35,000 RPM. I've done a lot of different stuff with it and the vast majority of the time it's set between 10,000 and 15,000 RPM; failing that, around 30,000 RPM. If you're looking at a tool that only offers 2-3 speed settings, I recommend one that has a low speed in the 10-15K range and a high speed around 30K.
~ Dremel is "the" name when it comes to rotary tools. If you're looking for a high-end, very versatile rotary tool, I recommend a Dremel (specifically, the one I've got) as there's not much available in other brands. However, if you're looking for a much more affordable but still decent rotary tool, Dremel's low-end models aren't any better or different than the competition (and are sometimes worse) yet you'll have to pay a lot more just because it has the Dremel name on it.
Here's the low-end Dremel model that's versatile enough for a decent range of applications and is capable of cutting metal. Note the price tag of $40 - better than $100, but very pricey for a basic model.
~ Black and Decker makes some damn fine power tools. I've never owned a B&D rotary tool, but I own a lot of other B&D power tools and I'm willing to vouch for
their rotary tool by name alone. Home Depot sells it, but I've linked to it on Amazon (about $30, same as HD) because the page is more informative. This rotary tool is actually a little more versatile than the $40 Dremel, though it comes with less accessories. It *does* come with two cut-off wheels, though, which is what you'd need to cut metal. They have
a very similar tool that costs $5 more but comes with a lot more accessories. All Dremel accessories can be used with the B&D tools.
Notes: with either B&D tool, you can save about $5 by checking out the "used" ones and selecting an "Amazon Warehouse Deals" option. Amazon warehouse is freaking awesome - I've gotten a LOT of used/returned stuff that way to save money and everything's always been as good as new.
Also, if you buy $50 worth of B&D stuff from Amazon, you get $10 off - yay, holiday sale!
~ Ok, $30 is nice, but let's see if we can do better...
Wen rotary tool - $20 at Home Depot. I've never owned any Wen tools but have seen them around and haven't heard bad things. The tool is variable speed (yay!) and comes with a ridiculous number of accessories. In fact, given the cost of Dremel accessories, this tool is worth buying JUST for the accessories! Only four reviews on the HD site, though, and one of them is written by a moron.
Let's try
Amazon. Only $18 there and Prime/Super Saver eligible. 33 reviews/3.8 star overall rating. Five 1-star reviews; all of which describe issues that were readily apparent during the first use - meaning if you were to buy a lemon, you'd know right away (and it's an actual Amazon item, which means no-hassle free returns for the first 30 days. As a note, I wholeheartedly vouch for their return system and customer service - I'm always very impressed). I'm actually about to buy one of these just because it comes with a whole lot more than $18 worth of accessories!
All Dremel accessories can be used with the Wen tool (and vice-versa).
In other words, the Wen rotary tool is more versatile than the comparable Dremel model, comes with a TON more accessories and is less than half the price. Sounds like a winner to me.
TLDR: If you need to cut the metal cord covers, my "best value" recommendation is the Wen Rotary tool, found on Amazon for $17.99. Unless you avoid DIY projects completely, you'll definitely get your money's worth out of this. If you'd get impatient with a hand saw, you'll get your money's worth even if you never use it again 
.
Note: You NEED safety goggles (cost: $1-2 at a hardware store or the dollar store) for cutting metal with a power tool. There WILL be sparks; hold the tool and metal at arm's length. Depending on how far away my hands are from where I'm cutting, I don't always use work gloves... but I also use power tools a LOT and am used to their behavior so I know how to keep my hands where the sparks won't land. If you're new to cutting metal, cough up the $3 for a pair of heavy-duty plastic work gloves. Also, avoid loose-fitting clothing.
If you need or want an even cheaper option, the alternative is a $7-10 hand saw from a hardware store and a LOT of patience. Show the cord covers you've chosen to an employee that seems to have a clue and let them help you pick out the cheapest tool capable of cutting through them - I can't really recommend a decent saw without looking at what they'll need to cut first.
