I am planning on giving each of my players a magic item that scales with then as they level. The reason for this is I plan to run a low magic item game and want then to still get cool ness as I level their items every few levels.
Because this item is going to (hopefully) be with them for the entirety of the game I want it to be something they think is cool. So I am planning to let them pick the magic item. They will get the item at level two, and it will be master work. If a player wants a masterwork long sword that is fine. But what if they want a Greatsword or Fullplate armor. I am trying to give them an item they can use at later levels but I don’t want to make them over powered at level 2.
How should I handle this?
Greatsword isn't a problem. You can afford one of those at level 1, even a masterwork one. Fullplate, on the other hand, is half of your level 2 wealth (according tot he WBL chart).
My recommendation would be to make it half-plate at level 2 that upgrades to fullplate at level 3 and then gains the +1 bonus with everyone else at level 4.
We are doing something similar in my game too. We liked things a bit higher powered, and so we considered this "legacy item" as apart from the normal WBL guidelines.