They don't put them out until the actual party. Several gift shops had them (Star Traders was where I got mine.) I believe they are different each year.
We got our MNSSHP during the party at a kiosk stand on Main Street. They were purple tye died shirts and were pretty neat looking. As far as cost goes, if I remember correctly, the adult shirts were definitely less than $20 and the children's shirts were less than $15. I could be wrong, but I really don't remember them being more expensive than any other Disney T-shirt.
Our Authorized Disney Vacation Planners are here to provide personalized, expert advice, answer every question, and uncover the best discounts.
Let Dreams Unlimited Travel take care of all the details, so you can sit back, relax, and enjoy a stress-free vacation.