some of these "frames" look more akin to an easel(for keeping a piece of enlarging paper flat) rather than a vacuum FRAME(which sucks a negative and paper together).

I got mine(18x22" Nuarc) w/ a pump from Craigslist for $50. I had to re-wire the cord with a new one and a new plug, but it runs like a champ and pulls about 35# at full force, probably more if the gauge wasn't topped out already . So all in all with new parts, about a $65 investment.