i've gotten them before from a cashier at a convenience store/gas station, she saved about 30 or so for me, all different states, they are quite cool, but the paint(or whatever the coloring is) will eventually chip off with contact over time.
If you keep it, I would put it in a plastic baggie or cardboard 2x2 for protection.
HH
Buff
p.s. they are not valueable. (not to let your hopes down), I am sure you already knew.