All hand books, tool kit, service history, accident damage, leaks of ANY engine fluids, lock operations, dash pixels and then the usual tyres etc. Don't let him tell you it's 'fully optioned' - I have never seen a fully optioned BM in all the years I've been playing with them.
Good - Fast - Cheap: Pick any two.
E23 735i; E30 318i; E32 735iL (X 2 - 1 White and 1 Light Blue); E34 535i; E38 735iL; R50 Cooper; R55 Cooper Clubman.
E21 318i; E32 735iL; E34 535i; E38 730iL; E53 4.4i