Puzzle Quest 3

It would seem this achievement is semi-misleading. Sure you can upgrade a piece of gear to level 10, but you can also just earn a piece of gear that is already at lvl 10. I did this by going through the story and got a free lvl 10 piece of gear in chapter 2. I would assume this will be the same for lvl 50 gear too. Will update when I'm lvl 50 to know :p

So you can be a little conservative with your upgrade spending.

edit: 146hrs later. Sure it's probably possible for a lvl50 item to drop but I mean yeah...good luck with that.