My twopence? If price is a concern, get one of the old rangefinders that take 120 film; it's a cheap entry into MF. Or you could do what Wayne said; I second his recommendation. I am, as in the U.S. everybody says, "partial" to all those options because I own a Hasselblad, a Rolleiflex, a Lubitel 166 and a MF rangefinder.
Too many options. You want quality at garage sale prices? Get a Rolleiflex with a 75mm 3.5 lens (I prefer the Xenar over the Tessar lens). You can get a nice one for about $300 if you shop right. If you want a 80mm f/2.8, then you're paying a premium; a good copy will cost you at least $600.
You can get a good Kiev 88 "CM" set for about $500; no pun, it's a russian roulette, the QA is a misnomer with those cameras, but when you get a good one they're really nice.
If money is not a problem, of course, get a Hasselblad with all the bells and whistles. Or get a Mamiya 7 with a few lenses.
Good luck choosing!