I doubt this quest is worth doing anymore. Cost is high in most cases, since it needs vitamins, rare candies and revival herbs, sometimes more than 1 for one step (are you kidding me?), and on top of that we can't refuse the trash pokemon like bonsly, mime jr etc (50% of the cases) so we are stuck spending items and time healing trash we will kill as soon as they are healed. Maybe it is best to hunt these pokemon in the wild. No items lost, except the pokeballs to catch them, although it may take a little more time to find one.