Personally, I wouldn't pay the asking price for a car without the service history printout (or invoices etc), simply because it will have a knock-on effect on the trade-in or sale value when you sell the car.
The issue is that MB won't normally release the service history to you unless you are the registered keeper, so while you might get lucky and the car will prove to have FMDSH, the fact remains that buying the car in the hope that it turn-out OK is simply a gamble.
Your options are:
- Insist that the dealer obtains the service history from MB
- Find a friendly local independent, or even a friendly dealer, who will agree to print-out the service history for you, in fact some members here have access to the MB Digital Service Book (DSB) and might be able to help
- If neither work, then check the car over carefully yourself and buy 'on condition': does the car appear to have been well looked after? Does it have 4 decent-brand tyres, of same make and model, and even wear? Do the discs look smooth or heavily grooved? Is the interior fresh or tired looking? Etc, and if you're happy with the car then buy it BUT only after you've knocked-down the price to reflect your future loss due to the (potentially) missing service history when you sell it.
Part of the issue is that the car may have been serviced by independent specialists who did not have access to the MB DSB, in which case if there are no service bills then this information is lost forever and the car's value will drop, even though it is actually a properly serviced car - not much that can be down about that.
As for the service offered by the dealer... unless he can get the service done by someone who can update the MB DSB, I wouldn't bother. He'll probably just do a quick engine oil and filter change, which will leave you neither here nor there, in the sense that you wouldn't know if the air filter, fuel filter, cabin filter, brake fluid, ATF, etc are due or not, and also the service will probably not include the various checks required under the applicable service schedule inspection.
What I would do instead, is decline the quick service, and after buying the car, take it to an independent specialist who will check what is due and carry the appropriate service and inspection in full then log it on the MB DSB.