We get to pay our services in full day 1 here in Greece (and in other places in Europe I assume). It is bloody expensive here not only to maintain an M3 but also to own it in the first place (price starts at E90,000 / $117,000). The only good part is gasoline cost which seems to be lower compared to the rest of Europe (not sure vs the US though). We pay E1.18/lt of V Power Racing (which is supposed to be 100octane although I don't believe it is).
Anyway, for the break in service I paid E400, which included engine oil change (9lt), DCT oil change (with the correct one!), and differential fluid change (I specifically asked / requested the latter two changes - the dealer said no need to do these). As for the cost of the castrol engine oil, the dealer sells the 1lt bottle for E17 / $22.
But we still love owning M3s here!! And there aren't that many arround so it feels kinda special!