So, I think first it's important to get out what entrapment is. Entrapment is an affirmative defense available in most US jurisdictions that allows a defendant to argue they had no predisposition to commit an illegal act prior to the government's involvement actions towards them. In order to get it, you have to demonstrate that an agent of the government convinced you to do something you wouldn't otherwise do. For that reason, it's almost universally unavailable to someone who has been convicted of committing the act before, and it is generally unavailable of the prosecution can provide 'more likely than not' evidence that the defendant has committed the act before. Some scenarios might help draw out just what entrapment is:
Undercover: hey guy, you want to buy a gram of blow?
Bar patron: Are you a cop? You know you have to tell me if your a cop.
Undercover: Naw man, I'm not a cop, its $60, you want one?
Bar patron: Sure!
No entrapment
Undercover: hey guy, you want to buy a gram of blow?
Bar patron: Naw, I don't really do that.
Undercover: Come on, It's a good time for only $60
Bar patron: Alright, I guess I'll take one
No entrapment
Undercover: hey guy, you want to buy a gram of blow?
Bar patron: Naw, I don't really do that.
Undercover: Come on, It's a good time for only $60
Bar patron: Not tonight man
Undercover: Ok ok, for you, I'll knock of $5
Bar patron: Alright, I guess I'll take one
No entrapment
Undercover: Hey guy, you want to buy a gram of blow?
Bar patron: Naw, I don't really do that.
Undercover: Come on, it's a good time for only $60
Bar patron: I'm just not interested, sorry
Undercover: I'll give you a special, only $30
Bar patron: I appreciate that, but no, I don't do drugs
Undercover: How about this, I'll give it to you for free, just try it with me, I think you'll like it
Bar patron: Alright, I guess I'll try it.
Entrapment may be available.
As you can see, entrapment's a pretty rare defense for people, the police really have to have convinced you to do something you wouldn't have otherwise done. Your bitcoin scenario doesn't seem to involve this at all, it looks like just an undercover buy, which happen all the time and are certainly not entrapment.
As for whether you could get out of a charge of trafficking because you directed payment to a third party, as the above poster addressed, that will absolutely not help you. You traded "something of value" in exchange for the drugs, it's a but-for scenario, you wouldn't have delivered the drugs if you didn't think they would donate, getting them to give something up in exchange for the drugs is a sale.
Yeah I don't know what he meant by entrapment, I think he meant how expensive it would be to the DEA and drug enforcement agencies if they had to deal with bitcoin; they can't just take it right back and recycle it for another deal lol.