Yeah....considering the person you bought it from could have asked $52,380 or as good as condition as you say it was....it could have gone for $55,135.
So yeah....congradulations

...you saved around $5,880 to $8,635!
I'm assuming it still has the 4 year/ 50,000 mile warranty...so you still got some time for the service help if you need it!
Good choice...IMO I love the new 7 series.....I hope you enjoy it as well!