Good buy or not..? on 1998 BMW 750iL

I just looked at a 98 750 w/ 100k miles on it. The guy wants 9500 for it. He states he "preventatively" replaced fuel lines, radiator hoses, and many other items which is great. But when I started the car, I smelled an overwhelming gasoline smell - like there was a leak? I could not see one, but none the less, it lingered for a while even after I turned the car off. Unfortunately, the seller was not present to ask him about it, but I thought the experts here could lend a hand - this car is pretty amazing, but I am wary about the cost $$$ to fix. Any ideas about this problem? Also, are there specific issues to the 750 other than the recall I found online? Thanks...

Asked by for the 1998 BMW 750iL
The gas smell could be any number of things, probably should have a mechanic check this car from end to end as these cars cost a fortune to repair