Same with motorcycles. I have a 69 Triumph that's currently in shitty condition that I'm going to be restoring and I've been offered decent money (given the condition) for it before. If I had it in perfect condition he would have offered a lot more.
7 series are clean, I drove one when I was a kid and was working detailing cars for a luxury car dealership. Unfortunately they're notorious pieces of shit and obnoxiously expensive to fix. In regards to the license plate, I'd agree with BlueYonder.