when i looked at a 5101 i also tried to take a few dollars off the list price and the AD told me that he does make very little on that piece. he stated that he does get advertising credit from patek on the $$$ volume of inventory that he sells.
as far as i know, some say production is 10-20 per year, but who knows - it's a keeper any way you look at it.
as far as demand goes, i think that it's on the rise. two years ago, you could get one from a grey market dealer slightly below cost, now it's over list price from the gray guys. and if it doesn't hit list price at auction, it won't sell.
congratulations, that is a fantastic watch!!! I also agree that the 5013 is another grail watch!
best,
pat