Which states are you missing? Maybe you should post them out in the forum, and someone can send it to you. I know how difficult is when you are looking for a one thing in particular. When you don't look they are all over the place. When you do they seem to not being any where.
I bought all the state coins with stamps too on a card. They came from Danbury Mint I think. I paid $16.50 for each card that tells about the state and has both mint coins and the stamps. The even give you the album to put them in. I plan on leaving them to my boys. I know thats a lot of money but they have never been in circulation. I really like them. They did try to get me to buy the other coins they have added but I declined those. I have paid enough.
I think Rita's idea is a good one as someone here could have one, be able to get one or even know someone from that state who has an abundance. There are advantages of networking.
My daughter and I have both been collecting them and we swap off. She's a lot more active at it than I am so she has more of them, especially the newer ones of parks and possessions.