I'm at level 91 and also see people with a lower level and higher stats. However I recently discovered a trick to maximize my stats with the equipment we get for free -- I don't buy stuff yet. First I check my stats in the arena, then I go to the market and equip a new item and then check if my stats are higher. If not I re-equip with the previous item and sell the item which is worthless for my stats. That way I managed to increase my stats faster then before were I tried to maximize all sub stats as well...