i agree w/ Vanessa! cheap toys can be found around the house….
toilet paper or paper towel rolls are GREAT! fold one end in, put in a few treats or kibble so it "rattles" and fold the other end. let pup destroy it for the treats.
soda bottles work well too, but make sure the plastic ring, the cap, and the label has been removed. fill w/ a few kibble pieces and let pup smack it around to get them out.
boxes work good too - empty tissue boxes or other cardboard boxes. fill w/ a toy or treat.
I give my dog whole raw carrots (peeled and ends cut off) to chew on instead of buying new chew things often (nylabones, bully sticks). it's a nice treat every now and then and helps clean teeth. (makes a bit of an orange mess though!)
use your imagination, find some tubes or boxes around the house, be sure no choking hazards, and supervise, and you'll have some cheap fun!