I'm in Denton and DFW craigslist as far as I can tell has a lot of people selling "vintage" scopes with round screens for more than they are worth and on the other end a lot of modern Tek and HP stuff at dealer prices.
But keep an eye open on Ebay. Back about a year ago I picked up a 20MHz Tenma scope for about $50, and a week or so later saw 2 pintek scopes close at $10 that I even posted about on the forum hoping someone would pick up. Not sure who got them but I don't think it was here.
There are cheap scopes on ebay in the $50 to $100 range. $50 will get you a 20MHz scope, $100 should get you a 100MHz one.
Double those prices for Tek or HP, but keep an eye out for BK, Kenwood, Hitachi, LG, Philips etc.