The original MB coolant was made by the German company BASF (a huge chemical company like Dupont) and was called Glysantin. Valvoline (US company) acquired the antifreeze division of BASF several years ago and became the official supplier of MB coolant. Fortunately, Valvoline also sells their MB coolant in retail channels under the name of Zerex G-05, which costs about US$9 at Autozone.
Dexcool is only bad if car owners leave it at low levels for extended period of time, which may cause rust-like residues in the radiator. Walmart has Prestone Dexcool for about $6.