I am very fair skinned, and I burn easily. The sample didn't seem like enough. I tried to buy some at the gift shop, but the ladies working in there said that is was really expensive and I would probably have enough in the sample. They said something about it being really thick and would cover more than it looked like or something. I swear it seemed they didn't want to sell it to me! lol I decided to try it. I thought I had enough (I did reapply), but I was burned in a few spots when I got back to the hotel that night. I definitely plan on buying some next time we go, and reapply a lot! This sunscreen, at least for me, seemed to come off in the water easily. It is also super thick and kinda hard to apply - not like any regular sunscreen I have used. Sorry I don't know the exact amount it was, but I know it was a lot more than normal (it seems like it was around $15).
They have the sunscreen for sale at the big gift shop at the front of the park. It is probably at the other stands, but that is where I went to get it.