42.5 cents per round is not bad at all for M67. It is fine surplus ammo that used to be much cheaper than it is now (like everything else)
SGAmmo still has cases of it, but they are
running $588 per 1120 (52.5 cpr) with free shipping before taxes.
I agree with GM, the hype of corrosive Yugo M67 is a bit overdone (as are the windex myths and whatnot). Clean your bolt face, barrel, and gas system in a reasonable amount of time after you use it and you're golden.