I don't really keep up anymore since I spoil my pets too much to begin with
, but I'll try to think of some things:
My blue cloud dust is more like 7 bucks at the petstore, but it depends on where you're at. This usually lasts me about 2 months.
I feed my boys Kline which I get from a breeder, its 1.25/lb! I did use Mazuri before that and it was about 7-8 bucks for a 2 lb bag which lasted me about a month or month and a half.
Hay is about 5 bucks; I use Oxbow and its goes quicker than the others but it's (in my opinion) better
Lasts about 2 weeks for me (depends on the chins, my boys eat hay like crazy)
I made my own fleece bedding, so I don't use regular bedding anymore but when I did I used ECO-FRESH and it was about 15 bucks; I don't remember how big it was but it lasted about a month.
You can get stuff like pumice stones, wood treats and whatnot from petstores or make them. Like Gray said it is the cheapest to make yourself but you do need to make sure they always have at least a few toys.
I get cheerios and dried raisins from Walmart for low prices
And to add on to both food and jean, she sells a few different supplements. I use some (again from a breeder here not far from me) but there is one supplement she told me was a recipe from jamie, I give them to my chins every MWF, but you can always ask jean and look at her store. She also sells the Chin Spin, which is good for chins as well.
Also know that exotic pet vets aren't the cheapest, so always make sure you have a rainy day fund stashed away!