Two years of Turbo M50 BMW : How reliable and how expensive to own?!

Two years of Turbo M50 BMW : How reliable and how expensive to own?!

My calypso E34 has had the turbo M50b25 in it for 2 years now so I wanted to discuss how expensive this car has been to maintain since becoming turbo. Spoiler: its just as cheap to operate now as when it was stock!