I would pay the middleman because they have access to a rare product (in several color combinations) that you are looking for. I would go in with a price in mind, no different than buying from a sole owner and try and come to terms. It doesn't really matter who is getting what portion of the funds if both parties are happy with the transaction price and product. If there are other reservations with that business (that does not need to be disclosed here on an open forum) or you are looking for specific options that's a different story.
Good luck with your search.