Just because the game says that you've reached the stat requirements, doesn't mean that you can just go in unprepared. (Checking the difficulty, optimizing your cross-class abilities for progress gain.)
I've been in a similar situation, crafting the EX version of the Ramuh lamp when it was relatively new. (Mats are around 8 mil) I went in unprepared and didn't have Piece by Piece cross class. Fortunately, I did have Reclaim, and risked the 10% chance of losing the mats, and retained them.
Did I learn my lesson the hard way? Definitely, I always double-checked everything when dealing with expensive crafts now.
At the end of the day, the developers aren't here to handhold you through everything in this game, and you do need to be able to prepare for things. I'm not saying every crafter has to go through an experience like this, but it doesn't hurt to do at least a bit of research before tackling an expensive craft.