I'd be more suspicious that bungie controls it if he sells yet another gun he's never sold before, next week. If you haven't noticed there have been tons of armor repeats, but in the last few weeks he's sold guns he had not previously sold. Right now there are only 3 guns that he hasn't sold (hardlight, universal remote, and thunderlord) if he sells one of these next week, my suspicious will rise. The probability is him selling one of those as opposed to a repeat is low. Not talking about individual probability, but about the combined probability of sold vs not sold yet.