Are you planning on keeping the tires? Are they in good condition? I live in the boston area and there is this shop that sells flip flop rear wheels for like $30 both 700c and 27inch. He also sells cogs for like $7. If the bb and headset are moving freely, you should be ok. Get yourself some toeclips and straps and a mtn bike brake lever. All that can probably be done for under $60.