You CAN get a Delica or Endura for $50 if you look hard enough (eBay). But even if the average street price is a few $ more, it's a great investment. You get a totally reliable folder with a strong and foolproof lock plus superior blade steel (VG-10). YMMV but I think Spyderco makes some of the best priced high performance folders at this point.

Re: CRKT, they have some interesting designs but I could never convince myself to get one of their folders. Their choice of blade steels like AUS-4/6 is a major turn off for me.