Can someone tell me why it costs $800+/- to alter the software in the MB computer to get more HP? If I'm not mistaken, it's all Bosch OBDII, just like VW, BMW, etc. You can get the procedure done in a BMW for $399, and unlike with powerchip, you don't have to send off your DME anywhere. Stick the tool into the plug, turn on the switch, and it's done.
Dunno about the OBD question but you can get a Speedtuning chip (I believe the company is in Austria but the U.S. rep is here in Maryland) for somewhere in the $300 range. They might have specific info on their site:
www.speedtuningusa.com
I had their chip in a T-5R Volvo and it transformed the car. However the gains with an NA (naturally aspirated - i.e. non-turbo) are not as dramatic. The guy there is Oliver and is excellent to work with.