The guiding price range is $7500 to $9500. With such low mileage I would expect yours to fall at the higher end of that range.

It's always a good idea to seek a second opinion and don't just stick with the big dealers, there are lots of independent specialist mechanics who are often more tuned in to problems than dealers. More importantly they often cost less.

It's always a good idea to get a second opinion when facing the prospect of a large repair bill on something like an automatic transmission. Independent specialists who are working on automatic transmissions all the time often have greater knowledge about them than the dealership mechanics who don't work on them every day.