I like this idea and it actually solves a problem of people not wanting to play a healer role which seems to be happening more and more often. However it would need to be on par with Demon's suggestion:
Quote Originally Posted by Demon6324236 View Post
Well, so far as the medicine market goes, adding the same grade of healing items as we see from temp items would be amazing for it, they do not have to be as powerful, but fast acting healing items which are powerful are the best thing to bring them back.
I'm curious why not make them as powerful and make them stack to 99? Any DD who opts for the potion healer over an actual healer would be sacrificing gil and dps. While the gil may be of little consequence the dps loss is something huge to consider as a DD and to me sounds like a fair sacrifice.