One thing to know is: Leave things like stats open so that you can always improve or change the mechanics at any time, plus the high end of the bar shouldn't be constantly be high so power creep continues on.
Just look at Runescape, allthough it introduces Armor and Weapons, the base maximum of HP you can have is 990, it can be forced higher with the highest armor at level 80 defence...in a game where anyone can just about train their stats to 99, everyone looks simular to eachover and very often, one strategy rules overall.
And by the "high end of the bar"? Smithing is a severe sign of this, the best "common" armor they can produce at the 90's-99 is Rune, the armor/weapons you'd usually wear at 40 attack/defence, the last rework they did to smithing was sometime during runescape classic when Steel used to be the 90 smithing armor....