Toyota Repair: overdrive failure in a 1996 toyota camry, toyota camry, red flags

Question
I am looking to purchase a new used vehicle and ran across a 1996 Toyota camry in good cosmetic condition and the engine seems sound as well.It has 160,000 miles on it and when I test drove it I checked to see how well the overdrive would compensate for the weak 4 cyl engine.I was surprised when it did not kick in.What do you think the problem is?I punched the accelerator to the floor several times only to find the RPM's race above 4,000 and no power.Is this an easy fix?Could it just be a fuse?If not do you know how much money it might take to fix this problem?

Answer
I advise you to not buy this car, a transmission that doesn't go into overdrive has a problem, the fact that the engine revs up but the car loses power is enough for me to see red flags pop up, avoid this one unless you're willing to put another transmission in it.