I think the RTX 4080 would be worthy if they charged £800 for the reference model version, it's still faster than anything from the previous Ampere generation, on paper the spec looks decent.
You get a lot of performance for a 320 watt card. In comparison, the AD102 die (RTX 4090) uses a lot of power for the increase in performance, relative to the 4080.
The prices are largely determined by the last generation of cards though, and there were several cards priced over £1000 on release that still sold well, unfortunately.
The RTX 4090 is a silly product at that price (£1,599 for the FE!) considering that it's not even the fully fledged AD102 die.
I really think £1,000 ought to be the maximum, reserved only for the very best of any graphics card generation.
The GPU market is a mess, because these days they never just release the whole generation within the same quarter, or within 1 month of the initial launch. You get multiple launches instead, with no apparent end.