It's not. Those engines were well-built, the w210 body has a few issues, but most of them are known and many of the issues were fixed by the 2001 body style. The E55 is a hell of a car, but I'd expect further depreciation. The engine bits cost more, the brakes cost more, the suspensions stuff costs more, and you don't want a drag-car. Otherwise, the E55 is quite a bargain for what you get.

__________________
- Brian


1989 500SEL Euro
1966 250SE Cabriolet
1958 BMW Isetta 600