I think a grey market is a white market that is friendly toward black market participants, i.e. a marketplace where no one sells anything illegal, but people who sell illegal things in *other* markets are *there* and you can talk to them to acquire information about the black market
Discussion
Selling loosies in New York (single cigarettes) in front of a convenient store cheaper than the cost of a whole pack if you were to buy from the convenient store and divide by 20, is a good example of agorism. The cigarettes themselves aren't illegal, but they were acquired out state without hefty taxes and fees, but the store owner in New York must incur those fees. The store owner is getting priced out by the agorist in this case. Is this a white market or black market?