read the Starmark warranty documentation for yourself...have the dealer fax it to you!
the added/extended Starmark is exactly that (added./ extended)....starts and continues past the standard 1yr/100K (that comes free on any Starmarked car)
the added/extended protection is available for just powertrain or both powertrain and more stuff....
the cost of Starmark extended protection is standard in the US
theoretically, Starmark- is an insurance policy and based upon the pricy nature of MB parts and MB dealer labor, is quite reasonable....why wouldn't you want to have a used MB covered with no deductible mechanical insurance? ...note, it does cover major items and not every little item...so become familar with what you are buying
also, ask to see a "master inquiry" for your vehicle prior to puchase...it will tell you the repair history+++