Infusing an exotic into another exotic should not require an exotic shard. If I were to just dismantle the exotic I would get a shard, so where does that shard go when I infuse it into another exotic? Using logic, one could assume that the shard required by the exotic being upgraded would no longer be needed, because it would be granted from the other exotic being infused into it. It sounds like a fair one-for-one trade if you ask me. However, this is not the case in-game, but I strongly believe it should be. It just makes sense. Obviously, if I infuse a legendary into an exotic it should still require a shard. Like or bump if you agree.