The title pretty much covers it. I'm looking for some cheap cavemen, medium sized, no steel weapons.
I would honestly say to check the local stores for plastic cavemen sets. I seem to remember seeing some at my local drugstore, but for the love of all that's holy I can't find any online...
I don't think it's going to be easy to find caveman sets at the proper scale. Most toy figures like army men are about twice the size of PF figures.
The easiest way to do this might be to find some barbaric fur-clad creatures, maybe troglodytes or even orcs, and replace their heads with humanoid heads and then paint them.
Prehistoric Life Toob
Sadly, I already have it, they are too big.
There is also mega minis.
I doubt he needs them 6 years later, but since the thread was necromancied I will note that while the people in the linked Prehistoric Life Toob are too big for humans, they're great for ogre or hill giant minis, and the animals are about the right size for megafauna.
If someone is still after cavemen etc try otherworld miniatures and warlord games.
Speaking of good for hill giants/ogres, maybe these Caveman Toys could also work for that sort of thing.
EDIT: if they weren't out of stock :(
EDIT Again: with a little extra blue/white paint at 2 3/4 in tall, the Viking Set might make some nice Frost Giants.