599 Seat Memory Button Failure

Hi, my seat memory buttons have failed. All other motor functions for seats and steering wheel are fine, but there’s no longer any memory capability. This is my daily driver and I happen to use the buttons several times a day getting in and out of the car.
The local dealer wants to change the entire assembly with all of the buttons for $5K. Considering that it’s likely a basic module that would be $100 in a BMW, the price seems ludicrous.
Does anyone know about either repairing this, or replacing it with a generic product?

Much appreciated!