I have a CPH-IAD flight coming up in less than a month. PE to C was $500 until exactly 30 days prior to flight, then dropped to $300. In the few days it went back up to $500 and has held there despite there being 19 open seats in C. I wonder if they've recently decided to increase the floor bid to $500 regardless of capacity. I'm still a couple weeks out so will keep checking.