Well if you get them retail its not quite as painful and if you are scaling its not that bad of a hit. If you are making 100-200/day, even at scalper prices the repay period is very short.
Thats besides the fact. Your comment is you would not make money mining on a 3090. That is incorrect. Jerod's payback analysis is correct if considering static crypto prices and very elevated scalper pricing. Those assumptions are for a point in time, not for overall profitability and for a startup in this climate.
Holding those assumtpions as a baseline, if you are pulling 1.5ghs for your mining setup, you should be making in the ballpark of $50/day. A $2200 3090 is paid back in a month and a week. Then its profit moving forward and the next card has a shorter payback period. That would be a pretty small operation.
Once a miner reaches a certain threshold, which will vary depending on the risk appetite, up front costs no longer matter. You have the blinders of a single card purchaser on. Once that point is reached it becomes a hunt for the highest output at the best efficiency.