Hexed materials.

[Kristal]

You can have one billion gil, able to afford full set of -1 plus augment item, but nothing you can do if nobody is selling them.

Provide some incentive for people to do them. Offer to do 4-6 VWNM runs with x million for each crafting material, giving out free cells to max droprate. Hell, give them the NQ if they want it.