I've never seen a MB fuel pump go out at that mileage but that is not to say it couldn't happen. I just had to change the one in my E320 with 251k miles and the wife described it dying about the way you described. I went ahead and changed out the fuel filter too while I had it down.
That is a high price for around here. Really ez job on that application if you ask me. It takes less than an hour to change and a new VDO unit can be had for around $200.
Be thankful the tank is only about 1/2 full
.