I got a really good fare for my trip next month -- under $500. Last summer I paid close to $800 going the auction way -- terrible. This time I found my fare through Yahoo (Travelocity) -- and I notice that the rates go upwards as one gets closer to an anticipated departure date. Had I booked a week prior to when I made my reservation, my fare would have been $20 less. Also NOTE that these low fares are extremely restrictive -- can't move dates, can't sell, can't give away unless it is to someone with the same name as yours (unlikely, of course) and definitely no refunds. Had I used my noodles, I should have booked directly with the airlines -- sometimes they have much better deals and are more compassionate to unforeseen changes in schedules.
And beware of auctions. It was a nasty burnt experience for me in more ways than one.