I'm in the same spot and even posted a similar thread here:
https://lateral-g.net/forums/showthread.php?t=56459
I thought everyone had solid advice then and responses.
I'm still in the same spot all this time later. I'm just going to slowly work on the TA. I've bought a 00 540i that's modded with everything I want to serve as the fun car while I slowly work on the TA. Maybe you could do something similar? I have another thread concerning great driving cars for under $20k. There were good suggestions given in that thread too.
Good luck whatever you do.