If the problem is sticking valves or pistons you could try a couple of things that may help before you decide to dump the car. One is to try adding a friction modifer (lubegard red is a good one to use). There is another equivalent one by another manufacturer - cannot remember the name. About $10 but you may have to get it online - I do not think most auto parts stores carry this. The other is to get a auto service place to do a fluid exchange - this may dislodge whatever is causing the sticking. My guess is that the trans was not frequently serviced and some clutch material may be sticking in some places.
Good luck.