GPUs are sure money makers or hold really good value in the last few years (if you can get hold of one).
my friend was lucky enough to get a 3080 when it came out. cost £640. got to play on it for about 10 months and made a £670 profit when he sold it
my current GPU cost me £750 and i bought it when it came out almost 3 years ago. i reckon if i sold it i could get about ~£400 for it if i decided to sell it. not bad to get ~50-55% of the cost back after almost 3 years of use.