Most people do it on their own since it's a pretty straight forward install, especially if you read through all the DIY on the forum. I had bought a modified CDV but after driving my car for awhile, I've found that there is no need to switch out the OEM CDV.
2007 E92 328i 6MT (RETIRED)
2009 E90 328i xDrive 6AT (RETIRED)
2014 E84 xDrive 28i 8AT