I just bought stuff online for my son for next year! 2T is longer. My son is 26 months and in the 75% for height and 2T jeans are still too long!! The Childrens Place just had their $2.99 summer sale, both my boys got new stuff for next summer for really cheap!
I have bought things up to 36 months for my little man (but he is small lol) I figure you can always layer soooo t-shirts and onsies.. swin trunks and pjs are a good investment... and if its cheap.. lol you can pass it along or sell it ;)