It would depend on the model of Rolex. The last one DH had we got a little over 1/4 of what he paid for it. He never wore it, so it was 'new'. (He's had Rolex for 40 years & was tired of them.) Unless you sell it yourself to an end user, you won't get the most value out of it. And the increase in the price of gold could be why your friend got what they paid for it. Who knows.
We also sold a Tag & a Breitling. One place refuse to even consider taking the Tag, ended up getting $200 for ($2500.00 watch new, no sign of wear) & the $10,000 18ct Breitling bought in 1999, had it had wear on it, they would not of taken it either. I got $2400.00 for it. Had an offer of $800.00 for it. None of these watches were sold to retail locations. We have jewelers that come to Vegas regularly & buy. I've always gotten a fair price from them, much better than the local shops.
Would be shocked if a jeweler would buy a used Yuman.
While the US is crazy for rolex, the world loves Cartier. The auction houses might disagree that Rolex holds its value the most. Cartier does very well at the sales I've attended.
Thought I heard, overall, Patek holds its value best?
Again the model of the watch is the most important.