Many are very difficult to find. Links to aid in finding collectibles eBay is a great auction site. At any given time, there are usually Josie collectibles up for bid. This link will take you right to the list of Josie items. You must first register with eBay to be allowed to bid.
Registration is free.
Flashbacks is a pop culture store in Chicago that has had some Josie items in the past. It might be worthwhile to call or email them on occassion to see if they have anything available. This link is to their website.