Plenty of reasons. Rich owner who only uses it when it's needed and has something more suitable for everyday? Or works in the city and commutes by PT? School run car?
I dunno what it should be worth. Some say the market for this type of vehicle is small - most want the diesels.
If that's the only reason... what's your car worth, what will the repairs cost?
2K? Good grief. Have you had more than one estimate? Is the noise constant or does it change with the engine hot?
I haven't worked on a BMW V-8, but on my old Rover it is possible to identify which tappet is noisy with a stethoscope. But with those you replace them all anyway - if one is noisy the others will follow.
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