Rags:

The labor for a bearing repack and a bearing replace are going to be DIFFERENT if the tech is doing the job correctly. Bearing replacement is accompanied by bearing race replacement. Replacing a race isn't rocket science, but the person doing it should know what they're doing.

Repacking does not involve race replacement. The book says to use a dial indicator to set bearing preload. There was a recent discussion of this point and like other discussions here, some believe you need to set preload with a dial indicator; some say not.

I don't know what type of facility you had your oil changed at, but I'd seek another opinion. Find a shop versed in MBs.
A siezed wheel bearing can cause grief to include damage not only to your car, but to your own well-being. I wouldn't put this off.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"