BT MOTO tune for my 2021 R3 GT was $895...not including installation. You send BT your ECU, they install the tun4e and send it back. Very short turnover time and real performance increase. Most of the gain is that they raise the redline so that is where most of the power increase resides!
You can just reload the tune after you get the bike back from the dealer if its gone. They ( BT moto) aren't going to charge you again. I'm putting on a slip on and manifold and I emailed them, and they sent me a new tune for it. No more money involved.