best bet for IRL dealing is to anonymously take orders and payment (bitcoin is nice), and then dead drop the product and anonymously send the drop location to your client. GPS can be used for determining the location of the drop, and for the client locating it. That way even if one of your clients is busted, they cannot get you in a controlled buy as you always drop the drugs and never hand them off. And the money is not going to be marked or tied to you either. Of course to make this system as best as it can be, your clients should not know who you are either. There are a few ways you can accomplish this, perhaps a few highly trusted friends can know the deal and spread around business cards with your anonymous contact information on them or something.