What about mandatory gun buy back program that only pays like ten cents on the dollar?
Then you have to run the math on violent revolution, which is going to be way worse because the number of dead people goes up instead of down.
Anyway, you did not seem to indicate how the value would be set for guns being bought back.
$750 per gun is actually low. If I were to take a median, as I probably should have, then the number would have been about a grand.