I dont recommend doing this job (DIY or PRO) without access to a lift.
Reconnecting the shifter is near impossible (if not impossible) from inside the car, and needs done from underneath it at the transmission.
The entire job from start to finish will take 2-3 hours. Lets call it 4 to be on the safe side.
The replacement after market part is less than 50 bucks.
With all of the above, a skilled indy should be able to do it for significantly less than 400-500 bucks.
Or you can do it yourself for less than 50, but make sure you can raise the car up in the air enough to comfortably and safely reach underneath it.
The Mercedes way of doing this is replacing the entire shifter: AKA huge waste. The aftermarket pawl is more than good.
One thing to keep in mind, there are 2 models of these pawls, 5mm and 11mm
Most R230 I ve seen are 11mm, but you cant be sure until you get the old part out. No way to check by PN, because the pawl is not sold from factory to use as reference.