this past week I booked the 1045am SEA-ATL-BWI (with a flat-bed 763, no less, but getting in ~11pm due to a 2+ hour layover in ATL) for a not-at-all-unreasonable $560 ... since I really wasn't interested in a midnight drive to DC, I promptly SDCd to the 745am over JFK (arriving at 550pm) which was selling at $1400ish