I collect sample slabbed coins. Samples are not graded but are usually in some form of mint condition. They are often produced in limited quantities to hand out at coin shows. Some are produced in a generic form to be handed out at the major shows. Others will have labels (and coin selection) to match a specific show. I just purchased an Innovation dollar produced for the canceled ANA convention in Pittsburgh (and so marked), and ANACS often produces slabbed quarters featuring coins from the state holding a convention or show.

Generic sample coin slabs are generally inexpensive - it's easy to find them for $5 or $10. I paid $20 for the Pennsylvania dollar slab.