AFAIK, was never one in Belz/Prime. There was one in the Premium Outlets that closed 2 to 3 years ago. Now there is one in Festival Bay, but honestly, you don't see a lot of good deals--mostly same prices as in the parks.
If you happen to be in the Studios, there is a tiny outdoor shop to the right of the exit turnstiles that sells discontinued merchandise at a discount. That's where you'll find the best deals.
Hard Rock Outlet, at Lake Buena Vista Outlets, has some really good deals. However, very rarely will it be "Orlando" HRC--it's merchandise from all over. Not a big store, but worth 2 minutes if you're in the area anyway.