You’re getting 20FPS at medium settings at 1080P I assume?
You’re correct that the current GPU market is terrible. I would suggest fiddling with your settings until you get a playable experience, and maybe keep saving up for a while and wait for the market to normalize (probably after crypto currencies take a dive again).
There should be some optimizations to the sim coming along with the XBox release (likely this summer). If after that you’re still not happy with the performance, you will probably have saved up a bit more, and will be able to get a more impactful upgrade at a reasonable price.