[RussEfarmer]

I'm pretty good at cheap computers if you're into it
A HP Pavilion 590-p0053w is literally the whole computer with a 6 core processor, $350 with free shipping. I can't remember if these have a graphics card power connector, if they don't try and find a GTX 1650 Super graphics card to put in it, it doesn't need extra power.
https://www.ebay.com/itm/124544555385?ep...GTR=1#shId

Not everyone is into the used computer parts thing, so here's this:
Ryzen 5 5600X 6-core processor, brand new, cheap and very quick https://www.amazon.com/AMD-Ryzen-5600X-1...B08166SLDF
Motherboard that will fit all the stuff without spending 1 million dollar https://www.amazon.com/MSI-B550-PRO-ProS...B089CZSQB4
16GB of completely average memory https://www.amazon.com/Corsair-Vengeance...B0143UM4TC
If you have your old storage drive you can use that for vidoe ghame :) and put Windows on this SSD for very fast computer https://www.amazon.com/SAMSUNG-MZ-V8V1T0...B08V7GT6F3
You can build the computer in the old case, but if you dont want to do that just buy the cheapest thing that looks good, or this https://www.amazon.com/Thermaltake-Tempe...B073668KDM
Graphics card is really hard right now since the prices are wacky. You can get good deals on really, really crappy graphics cards on ebay: https://www.ebay.com/itm/265360121704 this GPU is good for garry's mod and medium settings on new games but you can't really crank stuff

and as others said in the meantime I would try to fix whatever is wrong with yours so you actually have a computer in the meantime, if you say whats wrong with it we can probably help you out

edit: Quadro prices are bit lower used because of businesses selling old workstations right now.. This Quadro M2000 is gonna be pretty crap but its only $160 https://www.ebay.com/itm/194310084251
I did also find this Quadro K4200 which is a little bit more powerful and cheaper, but it's a lot bigger so if you get that HP Pavilion it might not fit https://www.ebay.com/itm/255178836356