I'm looking at flights for 2 adults roundtrip from Milwaukee(MKE) to Denver(DEN) Dec 26th-Jan1st. I was looking at the bidding option on PL and am not sure how that works or if it is worth doing for this trip. Any help would be appreciated. 2 days ago a flight with frontier was around $230 and now its up to $363. I'm wondering if I should wait or if the price will just continue to go up.