Hopefully, the main barrier between an overenthusiastic 12 year old kid purchasing a dangerous animal is the kids parents!
The core problem is supply and demand. As long as there is demand there will be supply. I think it's possible to reduce the demand by educating potential buyers. To me the exotic pet trade is similar in some aspects to the drug trade. Who do you target the dealers or the users? As long as the pet dealers are operating within the law our only options are to target (educate) the users and change the laws. However, simply changing the laws will have minimal effect as long as the demand is great and profit margins are high.