600 sl maintenance question

Hi,
I am considering buying 1992 600 SL, V12, with 122,000 miles from some private dude. I heard that the cost of maintenance is 3,000-5,000/year.
Is this DIY or dealer service price?
I am a mechanic, I have Porsche 944, (which is no way as complicated as 600), at least, I have all kind of metric tools.
Any observations/experiences will be appreciated.

The maintenance is not what I would worry about with this car because you can think of it as any other car needing oil changes and your basic stuff- brake flush, spark plugs, trans service, ect. ect. The common problems involve oil leaks and wiring harnesses. It is not uncommon to see a complete engine harness, both throttle bodys, and throttle body control unit all need repair. Just this alone could set you back around 4-5 grand in parts. Check all service records, if there has not been any MAJOR repairs yet--- look out.

Thank you, I will ask the seller.