All Retailers i know of are 18+. Parents buy them for kids no problem.
The problem is the placement in stores and parents, Both paintball and Airsoft are stuck right bewteen the toy section and the gun section in most stores.
I think Training Should include Parents. When i sell a simple $200 paintmarker to a parent that I know is buying it for thier kid. I tell them that any problem that is cause with this marker is an offence under the fire arms act: You should see thier faces. Then they want to get junior to the field for same safety training, then they might keep that thing under lock and key.
Education is key,