Congrats on getting bunnies! I rarely buy toys in pet stores for mine. If I do, they're from the bird and cat aisles instead. Shredders are fun, as are hanging wooden parrot toys with bells. Avoid leather and rope please, but sisal is ok for them to chew on. Plastic cat toys with bells are classic, as are hard plastic baby keys and rattles.
I buy small, untreated grapevine wreaths from Hobby Lobby, 5 for $1, whee! Untreated wooden discs with holes in them for stringing up, also cheap from hobby stores. Untreated willow balls from Pier 1, super cheap too. Untreated grass mats and wicker baskets from where ever I can find them: Pier 1, dollar stores, hobby stores, Walmart, etc.
I make a lot of toys, including hanging toys, balsa toys (balsa is lots of fun to chew!), cardboard toilet paper tubes and paper lunch bags stuffed with hay, etc.
Here's a great list of cheap, fun rabbit toys:http://www.adoptarabbit.org/articles/2003/Toys.pdf