Just remember next time check other places as well before you get your ticket from Priceline.
Many people, including us, dont like to buy anything from Priceline, except for the cheapie hotel bidding, is exactly like what you experienced - there is no price protection from Priceline purchases. I am not sure if you get miles - may be now since Priceline also sells tickets instead of blind bidding, then those from the "purchased" channel would earn miles. Dont know.