The tie rod is not really a big deal to fix, much easier than a trans swap. I would not worry much about that. But whatever broke the transmission has to be a pretty solid object so it could have bent the unibody.
The rust on the bottom of the car is something that can be fixed if you have a welder and lots of time. some 16ga for the heavy parts and some thin stuff for the body is all you really need. Chances are the floor is about to come away from the sides so if you go look at it pull up the carpet or crawl under it and see what you can see. If the unibody and front/rear control arm structure is basically ok then I would have no problems buying the car personally. But if it needed a huge amount of rust repair then I would pass on it unless you don't think you can find a better one. Depending on your area they might have all rusted away worse than that by now.
Then again I guess I am willing to do a bit more work than most people to get a rusted out POS back on the road so my opinion might be a bit off from normal people. Just look at it as an opportunity to do some improvements to the car while you are fixing it
