Here is a thought and correct me if I am wrong. But f Xur is selling the new version of armor that you own, it would be cheaper to buy new then to upgrade old. For example: this week he has the symbiote helmet for 13 coins. You could buy new version, dismantle old for exotic shard to level new version. Total cost =13 coins. To upgrade old version would cost 14 coins (2 shards) and 7000 glimmer total. That is 1 shard to upgrade and 1 shard for final level of new item. Now weapons are a different story. Since new version costs 17 or 23 coins depending on type. You can save coins by upgrading (total cost eventually 14 coins) but will have to pay 7000 glimmer to upgrade. So not a big savings either way. Granted it all depends on your urgency to upgrade. If Xur has your item to upgrade or is selling new version and if not, do you want to wait. Thought I'd point this out for those on a strange coin and glimmer budget. Happy shopping!!