For some reason BMW has always had absurdly high oil consumption limits... I never understood how anyone could think that 1L/1000km is considered "normal" never mind BMW's 1.5L/1000km.
My last car was a twin turbo engine and at the most after 6-7k I would be down a 1/4 of a liter.
That said, I'm already not interested in this car anymore... It's 2012 people, post up-to date information and pictures of what you're trying to sell. It's not rocket science that people want to see what is wrong with the car and posting pictures of the car when you got it xx years ago when it was in mint condition doesn't help your case.