Just for future reference, this transmission problem might have been avoidable if you had changed the trans fluid (and filter) every 30k miles/3 yrs. If you buy a used vehicle, unless you have documentary proof of this type of transmission service, you need to get on track with that type of servicing.
I have always followed this schedule with my transmissions, and I have never needed transmission repair, even on cars with mileage in the 170k category. On the other hand, we get regular posts in this forum from folks who had to replace/rebuild their transmissions any time after 90k miles, and it has always turned out that these transmissions were not serviced as I described.
Timely maintenance is invariably cheaper than the repairs that result from lax maintenance!