I don't know why he would need to drop the entire trans to see the pins. Maybe you mean dropping the valve body. $700 to drop valve body is crazy expensive. $700 to drop entire trans is reasonable. Anyway, I have two spare mechatronics (used) for sale. Buy mine or another one and have it programmed to your X5. Going this route would be $400 or so. Here is an example of a programming service on ebay:
https://www.ebay.com/itm/BMW-F-Serie...EAAOSwLB5elpDX

Also, here is a service not on ebay but explains what needs done really well:
https://bimmerscan.com/products/bmw-...f-6hp-8hp-dct/