Things to check for
I'm assuming by certified that you mean by MB Dealer Certified Pre-Owned, and not just "certified" by an independent used car dealership, which there are plenty of on eBay. If so, that's closer to the price range that an MB dealer would sell it for (depending on options of course), but I still think you can find it a bit cheaper or talk them down.
Things to check for:
1) double check and make sure it hasn't been in an accident, not all accidents are reported meaning a carfax/autocheck is useless.
Since most accidents occur on the front and back
- review headlamps (see if seals were removed or tabs broken) and tail lights
- check the paint (look for any flaws in color from one end to the other in case it was painted over/blended, particularly on the front quarter panels and hood, which is common auto collision practice)
- make sure all the lines of the panels, doors and hoods are lined up, make sure the amg sport skirt doesn't have any gaps against the body.
- Check the suspension and alignment, make sure even spacing on the sides of the tire within the wheel wells, also check height levels are even from left tire to right tire (front and rear).
Try this quick check, press the sunroof open/close button forward or backward all the way, expecting the sunroof should automatically open/close all the way (Express Open/Close). If it doesn't, that usually means the battery was disconnected. Repair facilities don't realize that the battery should not be disconnected and disconnect it anyway when doing more serious work and forget to re-sync the sunroof.
2) Double check when the new car warranty expires. MY06 models were sold in 05, warranty is based off delivery date not model year. Meaning the 4 year/50k mile warrrany will expire this year versus 2010.
3) Extended warranty, is this an MB extended or aftermarket e.g. GWC? Verify whats covered, keep in mind, ext warranties aren't exactly the same as the new car warranty, not all parts are covered. Some aftermarket extended warranties also have deductibles and reimbursement policies. Double check everything.
4) Alot of people who get the premium and amg sport package don't mind splurging more and get the additional options that you may not be aware of, e.g. Lighting Package, Electronic Trunk, Satellite, Phone Kit, Parktronic, Distronic. Make sure all those options are working properly. If electronic trunk, make sure it opens and closes all the way without any help. Parktronic/Distronic sensors / alerts aren't going haywire. Lighting package, make sure active curving works (hard to see) and that the headlight cleaning system is spraying and in sync. If with CD Changer check if it works, if you don't know where it is (it took me a bit to find it) press the silver button below the hazzard button. Most of these repairs should be covered by the new vehicle warranty.
5) Double check the tread life on the tires (particularly the rear) If low, see if the dealer will throw in a new set of tires
6) Vehicle rising feature, make sure it actually goes up (usually rear first then front) and remains level, left and right side.
7) If you bought it from an MB dealer, before you take delivery, there are alot of outstanding DTBs (Dealer Techical Bulletins) for this car, have the MB dealer do a VMI (Vehicle Master Inquiry) for any outstanding recalls and/or service campaigns associated with your VIN, e.g. update the COMAND system, these repairs should be covered by the new vehicle warranty. (thanks konigstiger)
8) If it has Keyless-GO make sure the unlock button actually unlocks the doors. (repair/replacement should be covered by the new vehicle warranty)
9) Make that all the handles are properly functioning, make sure the button on the inside of the handle unlocks the car, and the small button on the outside locks it. (repair/replacement should be covered by the new vehicle warranty)
Hope this helps
If I think of anything else, I'll update.