I'd bet good money that Bungie and Activision have already explored this option. Personally I think it goes against the idea of paying for the game initially, if Destiny were a free to download game like Warmind then that would be ok to sell weapons and armour (the developer needs to make money somehow) but since it's not a free to download game then I think it shouldn't be implemented. Unfortunately I think that we will start to see more and more game implement these kind of micro transactions which is only good for the developer not the players. All anyone needs to do is to look at how many games now have dlc's and season passes to see where all this is heading. Just my opinion. Everyone is entitled to theirs.