I recently did the 30k service on a 2000 2.7L Boxster for about $700 at the local dealership.  That also included a little labor to replace an oil filler tube that was leaking a little.  I've found these guys to be pretty competitive on most pricing compared to local independent shops and they've treated me well.  I think the price for the service was about $680.  Not cheap, but not a rip-off either.  I like the idea that all the things that could be wearing with age got checked and I know they're OK.  I bought the car with low miles so it wasn't used a lot over the years, but age alone can wear out hoses, seals, etc.  I found a list of all the standard things they do with that service and I'll look to see if I can find it.  I'm pretty sure I just searched on Google and found it pretty quickly.  It may even have been posted on renntech.
edited: just found the link to the checklist
http://www.renntech.org/forums/index.php?autocom=maint&code=maint_box_us_mj_02