I just had this done on my auto 10 speed and it was bout the same. $259 for labor and $144 for fluids. Also did the differential which was another $180. Differential is easy, the transmission fluid is hard to do because there is a process to get the fluid out and the car was to be at a certain temp for it to be added.
I have friends that work at Valvoline, so I had them change my transmission fluid for a little over 200$ because I've been busy and just didn't have the time. My 5th gen has 67k miles. I changed my rear differential myself. If you pay to get that done, it's a little over 100$
I have the 2017 2 SS with the automatic 8 speed transmission, I just had mine flushed because of the transmission shudder. Car has around 77,000 miles on it, and so far with about 150 miles on it since the flush the shudder has stopped. 🤞