Bought our 10 day Disney tickets here before we went. Got thenm from our travel company as they were on special offer, the advice is shop around for prices .
I like having them before we go & then we can go straight to the parks.
Our Seaworld tickets we bought from their web-site , again on special offer. We got unlimited admission for the price of 1 day.
We also visited Island of Adventure & bought tickets there at the gate - no discount.
not sdure if the above is of any help!!