There is a really great painting that was a collaboration between Bellini and Titian, it's a landscape with mythological figures. There is also some really great Dutch paintings by Rembrandt and Vermeer. Also a beautiful portrait by Da Vinci. I can g...
Consult with galleries that show Dutch work from that period.
A couple of his signed pieces were sold in Illinois (U.S.) last year for between $300 and $500 each..(sorry don't have the exact sale price) Each of the paintings were rated "fair" as far as condition goes....Check at a local museum, or art appraiser...