I know you can get items in smaller quantities from TJ's although they offer bulk items as well. I've ordered from them before.
I don't spoil my chinchilla like others do with toys and treats but he probably gets more attention than most. He has some pretty generic stuff you can get at a pet store including a lava ledge, a pumice stone block, a "Treat-K-bob" brand hanging toy (I contacted the manufacturer and confirmed they use vegetable dye), and pieces of parrot toys that my mom discards when she modifies them for her parrot. Rodents of any kind must have access to wood at all times to keep their teeth trimmed. Otherwise they can die of serious complications from overgrown teeth. Mine also has wooden shelves he'll sleep on and chew.
My chinchilla also likes anything paper and cardboard but he likes it too much and will eat cardboard to the exclusion of his food so I limit what he gets. He'll get TP and paper towel rolls, and he gets to play in a soda box when he's out sometimes. He also uses some plastic balls that I have but only under close supervision.
Printer paper with no ink on it is safe and so are cardboard food containers that are not plastic coated. So a cereal box would work but not a drink box. Certainly avoid plastic as it can get ingested and cause lacerations or obstructions to bowels. Cloth that unravels into threads can also cause an obstruction. I have used cloth handkerchiefs as a hammock without problems. My chin left the cloth alone but if you use any kind of soft materials you do so at your own risk. Some types of cloth are less likely to get chewed than others.
As far as treats I used to give raisins but now I give calf manna as a treat. I ordered that from TJ's and it's a good supplement for growing chins. It's very rich and too much can cause loose stools so you have to be careful with it. You can probably feed about a teaspoon of that in a day but only after the animal has had a week or so to adjust to it and only if there are no signs of loose stools.
Raisins are also good and can be attained from a grocery store. You can feed two a day and you can cut them up into smaller pieces. The sugar in the raisins can cause bloat if you give much more than that.