E39 M5 value

[eamo]

Being honest I don't mind the maintanance if I do buy one I'll be keeping it unless I'm forced to sell it....So would a higher mileage car be a no no..for instance that black one on donedeal has 170000 miles is that too high?

Ya - it will be hard to shift on when it comes to it. Hardly anyone wants a big miler M5
If one comes up for sale that tickles your fancy then go and look and have it checked mechanically. If it drives fine then happy days. I wouldn't go in thinking to myself I need to change vanos or clutch or bearings etc. A bonus if there done but really no need to address unless they start giving issues. A lot of M5's will have had a vanos or both vanos changed by now anyway. You can get an oil analysis done to see if there's an issue with bearings and a clutch is well ….. a clutch!
One more thing water pumps are very expensive IIRC €600 and there BMW brand only

Buddy of mine bought a very good one last year (ex members car that was on Donedeal) for less than 10k and has only had to do rocker cover gasket and timing chain tensioner
I was with him when he bought it at the time and if he didn't bring it with him I was going to!