So I had 55 coins. I wanted both the Armamentarium and Multi-Tool, but I would need two shards to infuse them into my Boolean Gemini and Dead Orbit chest. I infused my Arma first, after buying two and doing some screwed-up math thinking I could buy three Armas. Now I'm grinding coins to get a third Arma. This would've been a lot easier if Xûr just sold shards again, but at least it introduced me to Court of Oryx, which is great fun. EDIT: I got my MIDA! It only took 2 hours of CoO (at least I got Autumn Splendor,) but it's a beast!