If I could go online and pay the difference for first versus coach I would do it quite often. For me an extra $100-200 is often worth it. Today there is no way to do that so Delta is unable to monetize that seat with me. Anytime I've seen upgrades being sold at the gate ice been very confident I was getting one anyway but have told colleagues to jump on them. A $150 upgrade at the gate is a fair offer and a good way to monetize the seat. I know it means Silvers won't get upgraded but they can pay the $150 and do so.

What I think would be extraordinary would be to offer a tiered price based on status. $25 for Diamond to upgrade, $50 for Plat, $100 Gold, $150 silver and $200 for others.