If the most resource intensive thing you’re looking at is BG3 @ 1080p/60fps, you definitely won’t need to spend a few grand. Now is a great time to build. You can get pretty great price/performance at the moment.
Here’s a link to a build, I’d suggest buying the SSD in that list, and replacing your hybrid drive. You can keep the hybrid as a spare, if you want, but you don’t have to. If that solves your issue and gets you the performance you want, cool.
If it doesn’t solve your issues, you can just buy the rest of the parts in the list and build a new PC. It’s a PCPartPicker link for the UK, so it’ll tell you the best places you can order each part in your country. Alternatively, you can buy a prebuilt- probably wanna aim for $1000 USD or so for a prebuilt. I can’t really help you with that, not my thing.
If you do end up building your own there’s an extremely helpful very long Linus Tech Tips video that breaks down how to assemble the whole thing.
That GPU shortage absolutely blew. I used a 1650 the whole time, just sitting on my hands waiting for something to be vaguely affordable. Ended up snagging an RX 6600 right at the very very end of the shortage- caught it on a steep sale and paid $220 for it, and my exact model is $200 now so I did pretty good I think lol