Try and get it bought for 9K. Then take your 8-10K "get it right" money and get the mechanicals sorted. I would pursue a known good running 3.2 ( not saying that will be easy) and put the original motor on a shelf. If the body is truly straight either drive it with period patina or maybe wrap it for now. The interior... RS carpet kit is easy and cheap...find some budget used seats or recover the originals in cloth...both cooler and cheaper than leather or vinyl. $100 Momo. Drive it!
Seems you might have a fun coupe for around 20K. All of this is counting on you doing as much of the work as possible.....
If the market continues to rise price wise you will feel better about continuing to restore the car.....if not you have a fun quick weekend runner.
YMMV
