Sorry, but afraid you're too optimistic there. It's ofcourse subjective, states 1-5 (well....5....
), but 3K really really won't bring you to state 1-2, for that a lot more would be needed.
The trunk parts you'd normally wouldn't get from a dealer, then that figure is a LOT higher. More worrying financially are IMHO the leather-parts needing replacement (restoring would cost even more I believe), all electric-issues like the seats, you'll be busy for some time, but especially the respraying and so and if something should be wrong with it (since it behaves a bit different than with mine), event. the EDC-stuff. And this is what's know without a good test-drive so far.
BTW, as I wrote. THe replacement-engine came in AFAIR somewhere around 98K KM's or so. And then the replacement-one was driven for at least 50 r 70K KM's on 0W30 which is I believe also quite off. With all do respect, after 120K KM's now on it it's probably better than an engine with original 215K KM's on it, depending on the viewpoint and a lot of aspects one doesn't know now, but still shouldn't be overrated...
And to put it like this, when seeing how the car 'changed' in the past 5 years state-wise, even if it was brought to the dealer for service, I wouldn't be so sure than next to the interiour maybe nothing else was 'mistreated' IMHO. The missing 2 services KM-wise in the booklet give an indication of that already. Maybe I'm right with that, maybe not, one doesn't know.
But as all owners here know, an M5 is already part-price wise not exactely comparable to an E36 so a good basis with least problems to be normally expected is trying to play safe(r)...and getting one which is suspect a potentially expensive risk.
Either way, never get one without some 4 digits for it reserved in the bank, just in case .