Alright I don't wanna scare you away,
A 600 is one heck of a "first" MB, but yes dear, I'm sorry but it will cost ya to keep up. I've got a crazy bud down here that was given a 600 from his dad's passing away but he barely gets to drive it because #1 being the V-12 killer it is, just the cost of driving it is a mint in gas, each and every time he's had to even go to have something very minor done to it (like tighten the license plate screw or something), you can just hear the tech thinking "a 600 huh?... CHA CHING." $$$ MINT.
We switched up vehicles for a couple of days (because he wanted to use my 560 to pick up several friends from the airport and we know how much room the 600 has) and I couldn't stand the way that sucker drank gas! I'm not a lead foot and was very surprised that he actually wants to trade my other 560 for the 600 because it was more "economical" for him to drive:p
I almost took him up on it but I already hate the $$$ I spend on gas to keep the 560's going and that 600 was no joke! Of course he now has the 600 parked because he says it needs to be tuned up really bad and a tech says that some relay (that he has no idea what it is) is bad and will be about $740ish just for the part! It still drives with a slight miss but drivable. At one time he tried to get rid of it but even the dealers in the area wouldn't touch near what he wanted for it (which IS under the book value) because they say they'd have such a tough time selling it so...
As a bachelor he only drives it "out on the town" at times or for some special occasion as a "treat" for some woman to drool over while he drives by the lines at some club we may be DJing at on a particular night. As long as you can keep it maintained, I say go for it and if you can't afford to actually DRIVE it, make sure it LOOKS really clean, fully polished and waxed with wheels and tires prestine while it sits in the driveway. If the latter, also don't put it in the garage like anyone else with sense would do, just let everyone SEE that you have a 600 in your driveway so they'll THINK you've got it like that... You'd be suprised what people do, but then again, maybe not.
Good luck whatever you decide though!
P.S. Stu is the man down in your part of the woods though so you would have someone who is very capable and won't try to screw you (pardon the pun, but you get it)