It's nothing new. On a tour round the the Pattern room at the Royal Small Arms Factory in Enfield, we were shown a gold plated H&K MP5K that had been made for the bodyguards of King Hussein of Jordan. They even had a gold plated bayonet with gold scabbard (on an SMG!). Apparently Saddam Hussein had a couple as well.
It is alright is you can afford it, but just think of damage that a bit of scotchbrite could do the finish. They must be a b1tch to clean.