I owned an '85 500SEL. Great car, great ride, immense power. The thing only got 12-14 mpg and I could not handle that. I highly doubt it has only 84,000 miles on it, if it really does it should look absolutely brand new inside and out. Valve seals were a bit of a problem, if they are going bad you are going to use some oil and foul spark plugs. Timing chain and tensioner need to be done every 100-120k. That's about it. Oh yeah, and if it's a euro car, there is no way the odometer is accurate.