Not sure you approach Santos at all. Its third party ownership bollox isn't it? In which case, you speak to the agent/third party owner and they broker the deal.
As I said though, if Liverpool were prepared to pay 48m for Neymar, I wouldn't give much of a **** where the money went. I would care if we only wanted to pay 30m and had to pay extra for agents etc.
I don't know the details of Neymar's past ownership. If he was owned in part by Santos and in part by his father's company, then I guess the deal goes down in the same way as Falcao/Tevez/Masch's, with all parties sitting at the table and dealing transparently, albeit complicatedly, with no underhanded deals.
I'm afraid when the lines are blurry, as they actually were, the negotiations would then resume under the table the minute a competing bid comes along.

