Best place to buy prisms (not online)

So I do not enjoy purchasing things online so I decided that I would find a store near where I live that sells prisms. I figured a Teacher supply store would have them and sure enough they did! I got two prisms for 5 dollars each....idk how that compares to online prices but if it is a good deal in comparison and there is a teacher heaven or a similar store near you you could pick up these acrylic acute prisms without having to wait on shipping. Just food for thought.