Seaworld silver pass, makes sense??

[lynnfitz]

Hi-traveling this summer 3 adults. Will do Seaworld 1 day, maybe my son and I 2 days. The single day tickets are about $80, the silver pass is $180. The pass includes free parking, 10% off merch and dining, 1 free ticket, and up to 3 tickets at 50% off. I was thinking of purchase 1 silver pass to get the free ticket, and the one at 50% off. If my son and I go again, I could purchase his ticket for 50% off for the 2nd visit. Any thoughts? To me this made sense, but just wanted to make sure I wasn't over looking something! If anyone has done this, do you get the free ticket and 50% off ticket at the park when you arrive? Thanks!!
Also, we usually do go to Seaworld every summer, so I could use my pass for myself next year too.