When I first purchased the car 18 months ago, the air-con and the cruise control were not working. I had these fixed immediately and they have been working perfectly. The only cost I have incurred since has been to replace a distributor cap. This car is extremely reliable and well-built. All electrics and motors work perfectly. I paid top-dollar to buy an above-average condition model and have been rewarded with very low running costs.
I dreamed of owning a car like this in 1985 when it was released. Nineteen years later I was able to afford one and 18 months into ownership, I am amazed at how well it runs. Its power is more than adequate and the ride, handling, braking and comfort are sensational. It feels like a sturdy and safe car and I wouldn't want to be in anything less. It's still a head turner with a timeless shape and beautiful balance and proportion.
It is always a good idea to buy the best with available funds rather than buying a cheaper, poorer example with a view to restoration later.
The S class Mercedes (W-126) needs to be maintained well and a perfect service record is essential. High mileage should not be a deterrent if the vehicle had been looked after. I have a 1986 560 SEL with 149,000 km and it is still running almost like new. Forget about what Mercedes tells you and use the best of synthetic fluids for lubrication. I use Mobil 1 SuperSyn and Mobil 1 ATF.
Enjoy your 380!
Most MB W126 series enthusiasts steer clear of synthetic oils. Since 2000 I have put 90,000 km on my 1983 500SEC (Euro). See review "Magnificent and handsome." Now 325K! Replace timing chain (380SEC only has single width / 500 has double) and chain tensioner every 150,000 km. Engine oil every 5,000 km. And ENJOY!
Related to the above comment that "380 has single width" timing chain.
I'm told that only the US market 380 V8 engines got the single row timing chain, and even then M-B switched to the dual row in 1984 and made a kit to retrofit the single row chains with the dual row - aka double row or duplex.
For example, my 1984 Australian-delivered 380SE was equipped from new with a duplex chain.