Here's the number one thing that I feel like all people should be told before they adopt a rabbit: A rabbit is not a cat. A rabbit is not a dog. This is important to understand. A lot of rabbits do not like to be held, and a rabbit won't crave attention from you like a dog will unless you give it lots of attention already. Rabbits are not an easy pet to care for. Rabbits are not "cage" pets. They can live for about 10 years and the commitment necessary is similar to that of a dog, possibly more. I feel like these are the things that people don't understand, and this is why rabbits end up in shelters or neglected. This does not mean that rabbits do not make good pets. Teddy is a lovely pet, she loves to run around and hop over everything and she is so fun to watch. When she gets tired she lets me pet her head, and sometimes she'll sit next to me while I'm watching TV, and we can share healthy treats like fruits. Rabbits are wonderful pets; people just have expectations for them that don't match up with reality.
That being said, I paid about $70 for my most recent cage, which is pretty large, you can see it here:
http://rabbitsonline.net/view_topic.php?id=74891&forum_id=93
The cage is made from NIC panels, which has been mentioned above. I got her old cage for about the same price, and it had MAYBE 1/4 of the space that this cage does.
Costs for the rabbit can vary considerably depending on what you feed her. Some tips I would recommend for making the rabbit cost a little less can be found here:
http://rabbitsonline.net/view_topic.php?id=45023&forum_id=48
I find that Teddy Bear actually prefers her homemade toys to store-bought ones. Her favorites are paper bags (without handles!) She likes to hide inside of them, jump on top of and crinkle them, tear them, the possibilities are endless.
Rabbits aren't really "disease prone," except cancer is VERY common in female, unspayed rabbits. Spaying and neutering is essential for a pet rabbit. I payed about $115 for Teddy's spay if I remember correctly, my vet charged the same amount as she would for a cat spay, which I thought was reasonable. Depending on your area, the costs for a spay or neuter can vary considerably, although I don't think I would pay more than about $150.
Something very nice about rabbits is that, if they are spayed or neutered at a young enough age, and sometimes even if they are altered when they are older, they can be litter box trained. This makes cleaning the cage very easy and keeps the smell down a lot. (Although, after I got Teddy spayed, it takes several days before her cage starts smelling. Rabbits are not very smelly pets.)
I do hope that, after consideration, if you decide to get a rabbit, you will continue to post on here! It is a very helpful community and we are open to any and all rabbit-related questions. We're glad to help.