It is whatever your game plan requires; properly geared can mean that your character functions well as a hybrid; it can mean that your tank can soak up a certain amount of damage for an encounter (say 400+ magic armor or physical armor before buffs); it can mean that every party member is capable of one shotting most given encounters.
So, the question is, what is your game plan? Then you can answer what properly geared means to you. For me, it was simply to push damage, memory, bartering, and leadership as high as possible so I could be as flexible as possible in terms of buying power and deal with any given encounter.
