Sorry if I was confusing!
A set is 50 different 1.5 inch squares. You can send me as many sets as you want. If you send me five sets, that would be five baggies of 50 1.5inch squares.
Hope this helps. If it is still clear as mud let me know :)
Forgot that we need to put our names on the sets. A label on the baggie works great with your board name.