The party saves or meets a highly-skilled crafting NPC, or someone who employs one. This person owes the party a favour. So they tell the party about a bunch of legendary items that could be crafted… if only they had the final component. If the party can retrieve this component, the crafted will give them the item (a couple weeks later).
So it’s a promise of loot. Personalized loot.
And a setup to a (fetch) quest.
Of course, the component is used up in the process and there’s only 1 in the nearby area, so the crafter can only make one of the items on the menu. The party gets to negotiate and make appeals to each other before going on this quest. And, of course, they can always change their minds after.
Another option: each of the items needs a different component, so there are multiple plot hooks. If that’s what you want.