Oshkosh was selling them on line a few months ago - 5.95 or something like that, but the straps were still too long for my very slim 5 year old. The pouches are nice and small though.
I have seen the blue & red fisher price ones at kmart and wallmart. I have also seen lots of Dora fanny pack's, you didn't say if it was for a boy or girl but that may help. I have even seen the Dora one with a 4 pack of underware inside!!
TJ