United continues it's ridiculous ways. Offered a pop-up after purchase from SFO-DEN in First for $199. I declined. I immediately went to view my reservation (seconds after completing the purchase and seeing the pop-up and the offer was $129). No consistency on these offers. Plus buying first outright was $328. Since economy is $199 - the buy up after purchase is actually the difference between the economy flight and First class (surely no deal). The pop-up was an attempt to gouge. As usual United should be ashamed. Who would pay more than buying First outright?!