Father in law’s mid 2000s E-Class has done 300k miles, needed injectors along the way, but other wise been okay – it sounds rough though.
As above really, older ones – 80’s to early 90’s ones are brilliant, but not exactly exciting to drive or good on fuel – but they’re really well made and don’t look out of places in posh home county villages (if that’s your thing) and go for mega money even now – later ones rust and fall apart and are meant to be pretty terrible and then there’s the newish ones which are meant to be good again, but again cost fortunes.
If you’re only concern is VFM I wouldn’t bother, good ones cost to much and cheap ones aren’t very good – so they say.
I had a Honda Accord too, if you get Petrol one or a post facelift diesel you won’t go far wrong, huge boots, diesels are good on fuel and easily the best mile muncher I’ve ever owned – Cardiff to Morzine – easy, Cardiff to Loire THROUGH Paris on a single tank, stress free and easy.