Ninja can be somewhat expensive (not the most expensive job, but it's up there)
I reckon NIN is the current most expensive job out there. Maybe in part because ot one of the most used jobs atm, but i'm spending 300-400K per week on disposables.
Thats mainly because im on nin all the time atm, but I buy all the elemental tools individually as I need them for mnk too but try to stick to ice for azure as they the cheapest; I burn through Shihe, and Myoshu/miga and mob enfeeble tools im buying on a day-2day basis. Aswell as food, which I use yellow curry buns the job for me has shot through the roof in cost.
Fortunately, gil once at 90 is easy to make from farming pop items, so its not a problem, still it suprises me how much im spending on the job atm.