I wouldn't buy the one on Amazon - you can get an XS carrier (animals up to 10 lbs) in the cat/dog section of Walmart for like $10-15 that's perfect for a small to medium sized bunny. While there's no top door, it only takes a few seconds to undo some clips that hold the top and bottom halves together and then you can lift the whole top off - which is just as good a solution if not better.
The only noteworthy difference between the cheapest Walmart carrier and most of the more expensive ones is that the cheap one isn't "airline approved"... but if you don't intend to fly anywhere with your bunny traveling in the cargo hold, then that's irrelevant (only reason I even know about this difference is because I breed sugar gliders and will be shipping joeys via airline to their forever homes).
I've taken Nala and Gaz to the vet and such in one of the cheap carriers plenty of times (which equates to 8.5 lbs of bunny in a < 10 lbs rated carrier) and never had a single problem - they're very sturdy!