There is a delay of several weeks to purchase Obama gear from the campaign store.
ObamaCycle
The Obamacycle website will allow you to find folks that need your excess campaign material in the upcoming primary states. If you have excess material check the forums here and send your material to those that need it.
I have used this site to receive several hundreds of dollars worth of material. I shipped some of it to TX and PA and have used the remainder locally.
Hopefully this primary season ends in the next week, but just in case please redistribute your campaign swag.