Originally Posted by shipitfish

Booked today a round trip PDX<->BCN (via AMS in both directions) for travel in mid-April (Mon-Sun). Outbound was in a U fare and return was in an L fare. The L fare cost $130 to upgrade to a K, and the U fare cost $105 to upgrade to a K. Once all was upgraded to a K, it was 65,000 miles in each direction to upgrade to D1 for the PDX<->AMS legs. Cleared immediately.

I was so pleasantly surprised that the cash fare upgrade was so little! I have plenty of miles, but I'm on a tight budge cash-wise.