If you have a cat, or multiple cats, you know how hard it can be to find cheap kitty litter. Many of the cheaper kitty litters (and some of the more expensive ones) are environmentally unfriendly--and some even pose potential health hazards to your cat. However there are cheap, safe alternatives to kitty litter. You just have to expand your horizons a little bit!
Visit a farm and feed store. Chicken scratch and chicken feed is very inexpensive, especially if you buy a 50lb bag. It makes excellent kitty litter for pennies on the dollar. Because it is rather absorbent, it will help to control odor although perhaps not quite as well as some of the regular litters. However, if you have a covered, filtered box or the cat litter pan is in the basement, this won't be an issue.
Look at rabbit feed when you are at the feed store. Some rabbit feed comes in very small pellets that are a fine consistency for use as kitty litter and it is very inexpensive. Like the chicken scratch, it is absorbent and because it contains greens and chlorophyl, will help control odor. Because it is so absorbent it has some mild clumping action too.
Check the price of children's play sand at hardware stores. It is insanely inexpensive.You won't have the advantage of the nice clumping for the kitty urine and it will not control odor at all, but if your litter boxes are in an area where odor isn't a concern, play sand will work very well.
Shred paper! If you have a paper shredder and are on a very tight budget, finely shredded paper will do in a pinch. As with the sand, you will have no clumping or odor control with shredded paper although if you use newspaper it is somewhat absorbent.
Get your cat used to a new type of kitty litter the same way you get them used to a new type of food. Gradually add the new litter to their regular litter until they are using it without a second thought.
Appreciate the fact that except for the sand, these alternative litters don't cause any dust. Dust in some litters, especially the highly scented ones, can aggravate a cat's respiratory system as well as make the general litter area dusty. Concerns have been raised about the long-term safety of some litters for this reason.