Check this out first - on this car it's about a 4 Grand repair. I wouldn't buy a V12 without a serious pre-purchase inspection by a mechanic who knows a lot about V-12s.
This looks like a used car dealer that's selling ($149 documentation fee gives it away). If he's unable to move a car that looks that good, there's probably a good reason.
Although - high mileage does scare many people off.
Bottom Line - it's not worth an e-bay buy unless you can inspect it thoroughly.
I bought my E420 long-distance and had 2 separate shops inspect it (one that the buyer recommended, and one that I found at random in the yellow pages). It checked out and the car is great. Even with the inspection - the evaporator died about 2 months after buying it. I'm glad I talked the guy way down in price now.