A should take the $350. He made an offer and it was accepted.
On one hand, A’s annoyance is a little misplaced, as the involvement of the others doesn’t really change the substance of the transaction. A is still doing a favor for B & C. He helped them to get the gift they wanted, they are still buying the cabinet for the purpose they initially expressed, and they still benefit from the deal.
That said, the very existence of the dispute can be a poison to the relationships, as lingering resentment can fester and one or the other can feel uncomfortable around the other and gradually withdraw from the relationship. If money goes either way at this point, someone will feel bitter and resent it.
My recommendation would be sidestep the money issue, and for B and C to write A a note thanking him for the deal, along with a nice bottle of wine as an expression of gratitude. That way, A feels like his generosity is being acknowledged, and B and C will likely feel better because it is an act of generosity on their parts as well.
In some ways, this reminds me of a friendship conundrum that sometimes runs through my head. It is not uncommon to expect.a deal when dealing with a friend. But if the person really is a friend, shouldn’t you want to pay more than your friend would normally get, sacrificing a little on your end so that your friend is better off on the deal instead of expecting your friend to sacrifice for your benefit? The general rationalization, though it is often not a conscious one, is that you would give your friend a break if the positions were reversed. And sometimes things do work out that way when there is enough dealing between the parties.
At the least, though, I try to take advantage of seeing situations like this as a reminder to step back and think about nice things others have done for me, and whether I’m holding up my part of the friendship by looking out for them in the same way that they’ve lookes out for me. Which reminds me that there are a few people I need to share some particularly nice bottles with sometime soon . . .
I should just copy and paste this instead. Lol. New lawyers are so good at this 
What you typed is what it boils down to.
Nominal $ and initial purchase specifics aside:
A gave a deal to B&C b/c they are his buddies.
A got pissed b/c B&C syndicated the deal.
Assumptions:
-B is in a bit of a lurch b/c C is the one who did the syndicating and B is the one with the relationship to A.
-A can get rid of something easily and effortlessly through this selling channel and it would be much more difficult to get rid of otherwise.
-A, B & C are and want to remain friends
Given the assumptions above:
IMO C unknowingly violated trust but now knows A is pissed and B is in an awkward position. A is lucky to be getting out of the product so easily.
Solution:
-If I’m C: I make up the difference which isnt a big deal given the syndicate.
-If I’m B: same.
-If I’m A: I’m not pissed off in the first place since its an easy sale channel.
In other words just take the high road. And open a nice bottle and laugh at the silliness of all this.
If I were B, I would tell him he’s right, we don’t have a deal then.\
Then offer him $347 and throw in a tape measure. 
And then defriend him on Facebook. 
Yeah after reading this I voted that I would side with A.
Yeah, that’s my reaction.
Too bad I’m out. Otherwise I would have changed the original post to reflect this. I feel a lot of the votes are thinking too much about Craigslist, $50 etc.
The question is really just as simple as matt said.
Fu stated that the $50 is a made up number, so it might actually be a significant amount of coinage.
This almost feels like Friend A sold Friend B some SQN at cost because they are friends. Friend A gets upset because he learns Friend B sold “some” of the SQN wines at a profit. Or am I totally out of the ballpark here? 
Where does he say that?
I knew people were gonna get hung up on $50. But if I made the number larger to $500 everyone would swing the other way. So I just put a number.
Lets just say no one has ever asked me to write a test prompt before 
Can’t A just return it to Costco? Jkjk
Funny.
Some Berserkers swing both ways. Just sayin’.
A should sell B to D for $50 on Craigslist
Yup.
Obviously, the answer is that A bought a counterfeit wine cabinet on craigslist, is angry and wants to do the same thing to other naive wine cabinet buyers. Friend B and C, that sell wine cabinets for a living, sell it to D,E,F,G,H. They will turn around and give it to J (couldn’t use I without incriminating myself…). J will know it is counterfeit and refuse the tainted gift. The naive buyers will retaliate by suing A. D,E,F,G and H will win and be awarded punitive damages of $10,000…
best post. Use it for 5 years first and then return it.
Two responses. First, if the difference really is in the realm of $50, it’s not worth my hourly billing rate to offer a legal opinion on the contractual issues.
Second, A should be pleased he was able to offload an unwanted cabinet at about his cost, given he was a doofus who should have measured the cabinet in the first place. He should thank his lucky stars he didn’t have to try to sell it via Craigslist or some such.
Bruce