-
i would not sell something to someone for them to make profit from me
Every time you make any exchange, the other party profits from you, regardless of whether they make further exchanges with third parties using the same goods. Fortunately, you also profit from them.
You can go through life ascribing bad motives to market actors and make yourself miserable, or you can stop imagining that you have some mystical insight into their motives and judge them by the results of their actions. A got the item out of your way and paid you more than you'd have settled for, and then gave it to B for less than B thought he might have to pay. A might be a profiteering arsehole, but he has done both you and B favours by accident in the process.
B is the middle man who just wants profit and money, pretending he wants the frame, the pretending is the problem, i would not sell something to someone for them to make profit from me. Reputation of the forum decreases with dodgy users