Gil can buy you a lot of things.

Specifically, crafted gear is generally considered to be pretty high quality and the 3* stuff this patch I believe rivals some of the higher tier weapons and gear (save high-allagan and such). Melding materia to these pieces of equipment will give you even greater stats (stacking determination, Vit, Str, what have you) and help you power through content with gear that would be better than some of the stuff from soldiery tokens etc.

You can buy HQ gear and more importantly, if you don't want to spirit bind for ages, you can buy materia.