The issue is not the cost, it’s that many corporate travelers will get booked in the Y cabin and then can buy up to J on their own. Technically this has been possible forever with GG BUYUP if you get the right agent, but most travelers probably were unaware of it. Now it’s sold front and center in the app so I expect more upgrades to sell, more to happen spontaneously, and even fewer seats to go to RPUs especially before the gate.