For an M104 engine, an independent would charge about $1,200-$1,400 for just the head gasket.

If you decide to have the head resurfaced and to replace the valve guide and valve seals, then you'll need to add an additional $300-$400.

I'm sure the dealer's price would be higher than this.

FWIW, the new head gaskets have steel inserts that prevent them from leaking again.

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".