A buyer can be just as responsible for bringing an illegal plant in as the seller, in fact it is a common way for a buyer to get a prohibited plant they want, to go find a backyard grower and get it. Thats why they are making the buyers accountable now , as well as the sellers.
Buy or sell a plant illegally and you may be explaining, as you are paying the $10,000 fine, that you got busted by a cute little dog named Lolly, (she is one of the Ag dogs that are used now in the State of Calif. )
Food for thought, is it worth it? Do you want to risk having your property taken, lose your house, your money, and maybe your freedom?
http://www.ebay.com/gds/Selling-your-plants-on-Ebay-/10000000001404806/g.html