Weapon first on every job, no exceptions.

If weapon damage is +8 STR like at 50 (and I'm pretty sure it's higher now), you're gaining over 25 STR and 11 VIT. i180 chest to i200 gives 15 STR and 19 VIT. Small amounts of VIT and defence don't matter since fights are all about cooldowns. Every little bit of extra DPS speeds up a fight, helps skip mechanics and helps beat enrage. Plus, people that were smart and planned out their Alexander normal drops should be getting the i190 chest this week and finishing up the drops next week, while a weapon is the only thing you can't get from there.