Pietro Paolini or Dutch School?

At Vanderkindere, they sell on 21 April 2015 a "Dutch School, 17th century" portrait of a "Young man playing a mandoline", measuring 64 by 50 cm and estimated at 1,000 to 1,500 Euro. UPDATE: sold for 3,200 Euro.

I was also first searching in Dutch circles, people like Gerrit Van Honthorst or Hendrick Ter Brugghen, but by chance I wandered upon a completely different artist, the Italian Pietro Paolini. In 2000, Sotheby's sold a slightly larger (79 by 64 cm) version of the same painting, attributed to a Follower of Pietro Paolini. It fetched £3,600. I can't judge from the picture of that one whether it was a better or worse copy than the one for sale now (it was darker, but that's hardly relevant). The one for sale now is rather good, though not good enough to be a real Paolini probably. Which is too bad, as it would then be worth about 100 times as much. As it is, it still seems a very low estimate to me for what is a very decorative painting, skillfully painted, of considerable age, and in a very good condition.

By the way, the Saint George in the same auction is a reversed copy of Raphael's painting of the same subject.