I will say there are better options out there than just taking it to a local transmission shop. When my 6l80 went out completely (I was out of warranty unfortunately) I went to 3 transmission shops, all of which were in the 4-4.5k price range. I ended up just ordering a remanufactured 6l80 which had the factory defects amended (supposedly) with free shipping to my shop for like 2600 bucks. Got it from what's now these guys, https://reman-transmission.com/transmission-codes/?code=6L80. Shop only charged 650 to swap them out so ended up saving some money and it's been a little over a year now without any issues.