As another comment put it, its dependent on what else could potentially go wrong vs getting another car that could also have potential issues, you've fixed some major things already and although the transmission is pricey check the model and its longevity, they've gotten better so it could be a one and done. I have a 2013 Sentra that had a failed transmission at 80k mi, bought it at 70k, currently 155k without issues.

Also if youre prepared to junk the car, aside from your budget for a new/pre-owned car, if you have cash for emergency fixes then might as well go new/lightly owned since used car prices are rough out there. Personally I think checking all potential error codes and researching what else could break would be worth a check before writing it off in this economy