Back when I was in college, I bought a bunch of plastic toy figures from Dollar Tree, and a huge lot of variously-colored smaller plastic toy soldiers from a surplus store. I've found that as long as the PCs are distinct from both each other and whoever they're facing, we can keep track just fine even if the Elven Bard PC is being represented by a bright yellow horribly stereotyped "Indian Chief" figure and the kobolds we're facing are a bunch of tiny purple army men.

At some point I accumulated several boxes o' random figures at a library book sale, so now I have a bunch of older mostly metal figures I have yet to paint, and a bunch of plastic ones with bases that were probably for some game where you tracked something on the bases. (I also got several sacks of old Dragon magazines and random RPG materials. I think I paid a couple of dollars for all of this, because it was a small town library books sale on a Sunday afternoon and clearly no one else in this particular small town wanted a pile of old gaming stuff. I still haven't actually gone through all of it a decade later, but I have found some cool stuff in what I've looked at so far.)