There's a few schools of thought on the issue.
One being that at 140,000miles, the car should still have a bit of life left in it. Especially a fancypants Acura.
The other being what else could be damaged, and whether there'd be ongoing issues caused as a result. For example, if it's overheated and requires new cylinder heads, is the bottom end of the engine OK?
If you were planning on keeping it for a long while and it's been otherwise OK, then it might be worth doing the repair to get a couple more years out of it. If you have been having other issues and the car could continue to have problems, it might be worth cutting your losses.
I'll give you a little story of my own experiences. A couple years ago my car overheated on the freeway. It was worth about $4000 at the time, and the repair (cylinder head) was $3000. I decided to get it done, but unfortunately the bottom end was damaged and it continued to burn oil. I continued to drive it whilst topping up oil for the next year, until the clutch went. After that I decided to cut my losses and be rid of it.
As for what to get next, it depends on how much you drive, but a clean used (five years or so) smallish Japanese car is a pretty popular choice around these boards. Civic, Corolla, Mazda3, you name it. A Prius might also make sense if you're doing huge k's.
Also, move to an area where you don't have to drive everywhere :) Total car dependency is the pits.