I've only seen one guy do it, from black to blue, then back to black. Paint on the older, pre-2004 MBs is very soft so while it gets swirls very easily, it also loses them easily. A good detailer should have the paint in great shape in no time or you can learn to do it yourself (for example, Meguiars teaches classes on how to buff your car). As far as a proper repaint with color change (this cost more because they have to do inside the door jambs, trunk, hood, etc.) is probably going to cost around $5-8,000 to look like factory. If silver is a color you like, find the right shop as silver is a tricky color to get right, the flakes have to lay evenly or it will look blotchy also the body has to be very straight. It sound high and it is, painting a car has doubled in the past few years. You used to be able to get a decent repaint for $2,500 but no more, even bad work costs $3,500 and you wouldn't want that on an MB.