My first airhead was a '79 R100S. I still know where the bike is and who owns it. At one time I got to $12k on what I had spent on the bike and repairs. Bear in mind that bike was in great shape cosmetically and not crashed. I spent a lot on professional help that at this stage of the game I wouldn't have to. I'm perfectly fine with every nickel I've spent. All total I've had 5 airheads (still have two, although one is available) and I'd guess my total bill would be around $22k and I still own 2 bikes :)
I like airheads. Hope to never be without one.
1992 BMW R100GS
2005 BMW R1200GS