I found the Arnott replacement air springs (both front struts, rear air springs, compressor and valve assy) cost just over $1700. Where their coil spring conversion kit (C-3547) was under $1200. There are other companies making conversion kits ranging from 500 to 1700. Suncore, Strutmaster and a slew of Chinese companies. With the conversion you need a module that will prevent the warning light from being activated. That is included with some of the higher priced kits. I stayed with the air suspension and have not regretted it. It took me about 7 hours to install all the parts and the car has
remained at the proper height ever since.

__________________
Dave
88 300E 250K Sold
2000 C230K Totaled @104K
2003 ML320 156K Sold
2009 E350 4Matic Sport 46K Sold
2011 ML350 60K Sold
2014 GLK350 46k Sold
2012 GL450 67K
2016 E550 Cabriolet 48K