Not quite the same, but I paid the peak-season rate (120K vs. 80K) to go first class JFK-ICN on Korean Air in June. The peak rate is only about 6 weeks a year, but this was the best time for me to go, and I decided the extra 40K points was really only a "penalty" of $232.70, which is the amount in Staples VGC fees it takes to replenish that many Chase points (26 $300 VGCs). I don't MS much but I'll make the effort for the replenishment.

I haven't booked a standard award on a US carrier, though. The thought of paying double seems excessive, but I'd do it if I were still getting what I thought was a good deal compared with paying cash -- and I might still take into account the "How much does it cost to replenish the excess points?" principle.

Seth