Generally speaking, the "dark" years for Mercedes Benz were from about 2000-2008 though not quite so bad with the E class, as they are the default taxicab in Europe and HAD to be decent.

That said, there is about a 60% chance in one of the earlier w211 models that you could get one with "issues" on it.

Likely a 2009 would be the best bet if you subscribe to that theory.

So I'd try to get one with ALL books records and that the VMI showed no warranty visits on it, and that was for sale reluctantly and that had one fastidious owner that pampered it.

For these cars it's always best to get the best possible condition and complete history example you can, even if it costs more to buy.

And diesels are in higher demand than gassers so it WILL likely cost more.

An equivalent mint mint gasser would be possibly worth a look, and could less than a diesel.

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1991 560 SEC AMG, 199k <---- 300 hp 10:1 ECE euro HV ...

1995 E 420, 170k "The Red Plum" (sold)

2015 BMW 535i xdrive awd Stage 1 DINAN, 6k, <----364 hp

1967 Mercury Cougar, 49k

2013 Jaguar XF, 20k <----340 hp Supercharged, All Wheel Drive (sold)