You can only get to about level 6 and that's it. There is a point when everything you need comes from either a "Belt with Tools" or a "Box with Tools". To get a "Belt with Tools" you need several Forged Chests, which are really rare. And it looks like the only way to GET a "Box with Tools" is to get it as a reward by using items FROM a "Box with Tools". Obviously no one tried this game before releasing.