The only issue i have with reforging using materials to do so... is that it might suck for those who've broken down their armor and don't have a spare to go hunt the materials to make the repair kit. Money is just far easier...
Nothing worse then being high level, dirt poor, no armor to hunt the components down to repair your uber armor with. =/
However, I do think it's a kick butt idea =) Maybe if the item needed for the repair was something that dropped of most any monster like soul fragments once did? But then you run into the problem of having tons and nothing to do with them most likely even if you're repairing your stuff often.