They are selling out themselves and other gun owners.
They'd gladly pay it. The "anti money" isn't theirs, it means nothing to them, and they have more than you can waste.
I bet they'd pay 10 times that amount if they could get footage of your 1000 guys waiting in line to turn in guns. That'd be gold for them. It wouldn't matter why you were there, what signs you were carrying, or how loudly you sang Kumbaya. They'd replace the audio with voice over, and edit the video to make you look like a bunch of lunatics. A first year journalism student could spin that into looking like the "gun problem" is completely out of control, and you'd have people who normally wouldn't give a shit absolutely screaming for "something" to be done about it.
If some organization decides to hold a gun buyback, there is NO WAY we can make it work in our favor from a public opinion standpoint. The best thing that can happen for us is that nobody turns in anything, and the whole event gets ignored. Like almost every one of them.
They only win if they get guns.