I have always earned miles, elite bonuses, and been upgraded on priceline tickets on Northwest and America West. I have earned miles on USAirways. On America West, I have routinely gone standby for different flights.

That being said, you cannot rely on the above statement. Assume you will earn no miles and cannot change your ticket, as those are the rules. Priceline is very clear in that regard.

Finally, as for the economics of the argument of a $25 ticket r/t between PHX-LAX, versus a $100 ticket with miles and schedule flexibility, that really depends on the individual consumer.