Even though they are all marketed as gaming cards, Nvidia is now very clearly differentiating between 5070/5070 Ti/5080 for mid-high end gaming and 5090 for consumer/entry-level AI. The gap between xx80 and xx90 is going to be too wide for regular gamers to cross this generation.
Nvidia is also clearly differentiating the 5090 as the gaming card for people who want the best and an extra thousand dollars is a rounding error. They could have sold it for $1500 and still made big coin, but no doubt the extra $500 is pure wealth tax. It probably serves to make the 4070 look reasonably priced, even though it isn't.
Leaks indicate that the PCB has 14 layers with a 512-bit memory bus. It also has 32GB of GDDR7 memory and the die size is expected to be huge. This is all expensive. Would you prefer that they had not made the card and instead made a lesser card that was cheaper to make to avoid the higher price? That is the AMD strategy and they have lower prices.