2002 Honda CR-V Automatic Transmission Leak

My 2002 Honda CR-V has developed a small transmission leak - I am certain it is the transmission because of the smell and color of the fluid. It only leaks when I drive - not while parked. Transmission still works fine. Car has about 130K miles and I keep it in storage for 7 months/yr, currently driving about 4K/yr. I think it is the output shaft seal leaking, from where I can best see where the leak emanates. It makes sense, given the car’s age. Any idea on how much cost/time this takes, or should reasonably take, to repair? I had the tranny flushed & new fluid installed a few years ago, at 88K mi.

Also, I would have to drive about 90 miles to reach a specialty transmission shop or Honda dealer, but have several good local engine mechanics Is this a repair most engine mechanics can do, or would you take it to a dealer or specialty shop?