Remember when you only needed to pay £500-£600 for the top end GPU we thought that was expensive. eg 980ti. Anything over £1000 is stupid money nowadays. I bawked at the idea of paying £949 for my 3090. It will be my last high spend GPU period. If you can afford the 5090 for £2000 or whatever it appears at all power to your wallet not one to be-grudge your spending power but from a personal standpoint last few years I've got off the upgrade roundabout.
I doubt this time you have to worry about bots there will be plenty of stock.
My 4090 really held its value, in fact yesterday I sold it for a profit. I think the 5090 will be similar. With regards to plenty of stock, people were saying that a few days ago about the 9800x3d launch and it lasted about 10 minutes lol. I'd like one high end launch with it readily available before I believe it lol