What really gets you in trouble is when some dealer has a sale or they list something as a "gunsmith special". Here are a couple that I got:
Yugo 24/47: 2 for about $50 each. Both needed firing pins but otherwise great condition.
Yugo SKS: Got them for about $39 each, but the bores were pretty bad. Used one to build up a receiver and barrel that cost about $30, the other I kept and while the bore is pitted, it isn't too bad.
M44: Again, the gunsmith special was like $39 or something, but the only problem is that there is some pitting on the outside of the barrel and receiver. Looks real nice.