Does anyone know the cheapest place to purchase Propecia? It's $180 for a 4 month supply from my doctor.

That's a decent price for non-imported non-generic (and totally trustable) Propecia. (45 bucks a month).

Is that totally unaffordable?

You might ask your doctor if he would prescribe Proscar, which is 5 mg Finasteride, and divide it into quarters. This is a cheaper way to get your Finasteride (same drug as Propecia, just a different dosage). Ask your doctor, and tell him if price is an issue, because some doctors will be sympathetic. He'd probably rather have you use Proscar than nothing at all.

If you can afford the 45 bucks a month, then you can feel confident that you are not getting bogus drugs from a bootlegger.