Looks about right. These guys have great prices on factory parts.
http://catalog.mercedesshop.com/
I got my motor mounts from them at a fantastic price! Tell them you are from club202 forum as they appreciate the internet business.
And these guys have great prices on the shocks. Plus they can honor your warranty unlike the guys on ebay. $309 shipped!!
http://www.eshocks.com/bil_make.asp?Group1=Cars
Im not sure about the bolt kit. I would have thought Mercedes would use aluminum bolts? Oh well. I would probably go to a part supply house and just buy grade 8 annodized for a few cents a bolt. thats the strongest commercial grade plus the annodizing keeps them from rusting. Standard grade 8 will work. If you want to get really nutty you can order aircraft bolts from pegasus online... Thats the strongest bolt they make and Im sure its still less than mercedes bolts.
http://www.pegasusautoracing.com/?iorb=4764&BR001
Im still kicking this job around as well. Just put it in the air and look for cracked rubber Check your motor mounts for brownish yellow goop spraying/oozing out! Time for a new mount if so.
I am trying to get BMS to make more c43 cat back systems since my resonnator is cracked.. so you might hold off for a week or so if you want a killer stainless system.