Seeing as I've exhausted all my ideas on why he sells what he does and how to predict the next sale, I've come to this - I think Xur is now purely for new players. If so, I think it's a good idea, I mean everyone over a certain lvl surely has at least one exotic, right? Well why shouldn't every new lvl 20 have a yellow too? If this is what's going on, he's not going to sell something everyone else still wants (a la Gjally, HL, Red Death etc) so will be the least coveted ones. You're new? Want an exotic? Here, have this one. It's not the top dog (Icey B excluded) but it's exotic :) Think about this too - a new player hitting lvl 20 or so has very limited access to exotic drops. No Nightfalls, no raiding. But the more experienced players, who seem to comprise of the majority of the Xur haters, have access to every possible exotic drop/reward chance. Could this be it?