Short answer: You're probably going to be disappointed.

Long answer: Outside of a few specific cases, the loot pinatas are too effective to make crafted gear worth the trouble. When a new patch hits, crafted gear might help people pushing the bleeding edge gear up a little more quickly (and a lot more expensively), until gear from drops/tokens overtakes it (depends on the patch and the gear and what they've already got). Or if someone has just hit level 50 and has tons more money than time, crafted gear can let them jump iLevels to get into more content faster. There are also a few cases where fully melded crafted gear (pretty much just accessories) can help someone tweak different stats (e.g., tanks trying to push more STR instead of VIT). If you've got friends in those situations, you could (maybe) help them save some gil. For most players, it's not at all necessary and would at most be a temporary perk.

There are the relic quests, where everyone needs a specific crafted weapon with two specific materia attached, but the materia are (generally) the expensive part of that, and you really can't do much about those.