You can purchase a Harry Potter wizard chess set online at and at addition, you should check eBay because Harry Potter wizard chess sets are often offered for sale on eBay as well. The set is out of stock on the Barnes and Noble website, but may be in stock at a Barnes and Noble store.
Amaznon's website shows two Wizard chess sets available as of 10:00 eastern time this morning. They sell here for $122.00. The Barnes and Noble site shows they are out of stock online but you might have luck checking their stores if you have any in your area. Of course, you should aways check ebay too.
The noble collection has a great amount of Harry Potter paraphernalia. In case he's on the younger side, let him know it will not actually work like the one in Harry Potter (moves magically). But the one in this catalogue is the official chess set.