As long as you are willing to put up with Priceline's limitations (no control over times of travel is a BIG limitation to me), Priceline *can* work. I have used it for business and leisure travel, and once for hotel ($85 hotel room for $50, with an additional 1 free night promo deal).

Yes, it's best for short-notice travel when regular prices are a fortune, and you have the flexibility of traveling anytime on a given day. Theoretically, however, you need not use the magic Saturday night stay.

About FF miles: I recommend you send your ticket stubs through the mail, and see what happens. You might get lucky ...