I replaced the water pump on my CTS-V in my driveway. It's an LS motor..no big deal. The water pump was ~$200 instead of ~$100 for the Corvette version, though (different pulley depth). Brakes weren't bad either, ~$90 rotors and ~$60 pads, IIRC.
Yep everything on my CTS is cheaper than my Mercedes, and I work on my CTS a lot less.
Just got to the 1 year mark on the CTS and only thing I have done so far is tires (hated the Michelins on it), oil changes, and added a rear view camera.
My Mercedes after 1 year was cam seals (known issue and Mercedes updated them but you still pay), many transmission problem, oil leaks, fake leather seats coming apart (60k car and no leather), sun roof cover failing, oil changes (filters are not cheap), tires, etc... It why after just 1 year my wife was done.
My SiL had even more issues with her Audi. Not so much now since she switched to Lexus.
Have some customers now with a Saab and VW, they see me more than any other customer has so far and I only do this as side work now. The VW was towed here last week for its 3rd coolant leak this year.
Yea the Corvettes always get different pumps for some reason. My 73 has a regular small block so most think its either the short or long nose water pump... nope. Its a special Corvette length water pump.

But I am going to convert to electric fan and a Serp belt system and use a regular Camaro reverse water pump.