20,000$ seems high for that mileage. I bought a 1990 convertible for $7,000 with 65,000 miles on it. Perfect condition other than the AC needs work. He might be able to get $7,000-10,000$ but 20,000 is a real dream IMO.
It's a fairly common problem. Some people just tie it back on with bailing wire or something. Others have took the time to drill and tap the lever so a screw can be used to hold it on as shown below
Opened the post to view the photos of some mighty fine looking Reattas. Ronnie's red one is a standout (so is his landscape choices).
However, noticed the post about the key issue. My '89 had an issue (maybe not the same as bghere), but the key was sometimes hard to turn in the ignition. And, if it didn't turn, the trans would not move out of Park. My dealer replaced the ignition lock cylinder with new keys included. Cost (in July 2016) was $139 - $51 for the cylinder and balance for labor.