I believe this service (called the "B" service... a COMPLETE service!) is something like $400-$500 for an 8 cylinder model at the dealer (avg/general estimate). I believe that the 6 and 8 cylinder service cost is pretty similar. It's the 4 cylinder and 12 cylinder models that are a handful lower and higher, respectively. And that cost includes parts AND labor, to my knowledge... unless of course, replacement parts are needed.
I would find out (if you haven't yet) what the selling dealer normally charges for a 30k mile service on a 95 SL500...
So, yes, I think $700 seems quite pricey (but still possible I suppose) for a B service on an 8 cylinder.
2006 E350 w/ 155k miles (Daily Driver)
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)