I did Zazzle.com for DS's and DH's t's this last time. Wanted obnoxiously colored/bright t-shirts wiht star wars themes for one day. Got Dad a tshirt with Mickey, Goofy and Donald w/surf boards and one for step-mom with Lady. All personalized. I think I spent around $18 for most of them and got just what I wanted. As an added perk, I got credit from Sunshine Rewards by using their link!
I purchased DS and I Pooh sweatshirts (if you want them, you'll have to go back to Pooh corner!) when we were there in April. Mine was $56 and his was $48 (I think). They were embroidered.
I had planned to buy DD a t-shirt. Didn't really find anything that was stand out great, and everything was very very expensive, I thought, so we skipped it.