With what the GPU will cost you will not see the price of a better PSU as more than a speedbump. You can also sell your old one to recoup some of it.
Even so, 1KW+ personal computers are a bit strange, back in the day the very largest workstations (think IRIX fridges) were in that domain.
What would be nicer would be if manufacturers aimed for minimal power consumption with the same performance as a previous generation to give people the option.