Short answer - Yes. If the car is want you want and you are prepared to spend time/effort/money over the purchase price then buy it. If you want an easy shift to your new ride - walk away. Some other person will buy it and either love it to death (as you seem to want to) or just drive it into the ground.
Good - Fast - Cheap: Pick any two.
E23 735i; E30 318i; E32 735iL; E38 735iL; R50 Cooper; R55 Cooper Clubman.
E21 318i; E32 735iL; E34 535i; E38 730iL; E53 4.4i