Suggest you take a look at "Refurbished" computers from the usual mfrs. When doing so, consider PSU wattage, CPU, Gfx card, and type/capacity of storage drive. The larger the case the better, as Gfx cards are not getting any smaller these days. The reason for "maxxing-out" the refurb computer is that when doing so, it will likely come with all the fans and so forth necessary for the upgrades.
For example, my Dell XPS 8930 re-furb came with I5 CPU. Upgraded to same power-draw/wattage I7 CPU. THEN upgraded to higher-wattage I9 CPU, so had to buy an upgraded Dell/Alienware CPU cooler.
A friend of mine is awaiting delivery of an HP refurb, which he "maxxed-out" at my suggestion. I think he will pay maybe $900 all-up for a damn good gaming computer. He >>might<< need to spend a little money for RAM upgrades and perhaps a high-capacity SSD, but the fundamental guts are there.
PSU, CPU, Gfx card, and storage drives can usually be retrofitted, as desired. Critical to upgrading CPU is socket type, Chipset compatibility, and proper cooling.
Concur that "high-end" CPUs and Gfx cards are in short supply nowadays, and bring premium prices when found. A good "Refurb" computer, "maxxed-out" should serve you very well, and can likely be upgraded when price of desired components comes down. A bird in the hand is worth two in the bush.