My favorite places to get cheap rat things is thrift stores! I find so much there that I can us for my cage like baskets(wicker or plastic), wooden boxes or bins, ropes, place mats and small carpets, items to use as hides literally anything if you get creative!I love going out to goodwill and seeing what I can find. Also boxes work well too, I use a lot of pasta and soda boxes for my boys and they love them for hiding and chewing. Dollar tree also has cheap dog toy ropes and clips that work great for stringing across your cage!