I would vote for the transmission flush. Typically they will back flush fluid through the tranny that will essentially "clean" the filter in the process, so no filter change is required. And the prices you list for that process seem very reasonable to me. My SRT had 86K on it when I bought it this past April. In less than 1000 miles, my tranny started slipping when I would drive it "spiritedly". The dealer found a code that said "improper gear ratio", so instead of doing a back flush, I had to have them drop the pan to see if there were signs of abnormal wear in the transmission. Luckily, none were found and I had them do a back flush as well once they put the pan back on to ensure all the old fluid was out of the convertor. Since then, it has never slipped again, so I think it was worth it.

On a side note, had tranny problems with my '99 Dakota at 70K. Had a back flush done on the tranny and she just turned over 147K and is still running strong.

RL