You can see in the pictures, the Platinum package dress/tux have more fancy embroidery than the Free/Gold package dress/tux. You also get the Free/Gold dress/tux in addition to the Platinum dress/tux if you pay for Platinum. That's why you get 2 sets if you pay for Platinum.

I don't understand how the wedding reservation system is supposed to work, I wish they would explain that better.