Might I respectfully suggest either a Moskva-5 (6x9, Tessar-copy coated f/3.5 lens, folds to a little bigger than a 35 mm SLR body without the lens) or Iskra (6x6, similar lens and folds even smaller)? Both have coupled rangefinders, the Iskra has automatic frame counting (if it works -- many have been converted to red window), and while they're bulkier than a compact 35 mm rangefinder, the negative size makes it worthwhile. Either can be had in working condition for under $100 (though the Iskra is a little riskier, with the relatively fragile frame counter).

I have a Mosvka-5 (including the 6x6 format mask) that cost me $72 shipped from the Ukraine, and the only major complaint I have with it is that it's hard to get a good steady hand hold. Since I bushed the tripod mounts to fit American tripods, it's given me some really stellar images...