The indie mechanic I use has had issues in past with customers sourcing bad parts, so was dead against it. So it was all MB parts until the starter motor, which I baulked at & he did source an OEM part at half the price. All costs are in €uro, so bear that in mind & incl labour & VAT (on holiday atm so don’t have breakdown to hand):
Compressor (MB) €1,200
Diagnostics, software updates & service (I provided oil & filters) €270
Aux Battery- in passenger compartment (MB) €400
Starter Motor (OEM) €600