Why doesn't everyone go to the blue fairy instead of Rumple for help?

From what I've seen every time someone goes to Rumple for a deal, it always ends badly. Rarely ends good. It just doesn't make sense to me how David, Snow, シンデレラ and other ヒーローズ go to a villain for help. Why can't they go to Blue? または find a sorcerer または sorceress who conjures good magic and go to them for help? I mean going to Rumple, it's cost Snow her mother's necklace, Cinderella's husband and almost her baby though シンデレラ and Thomas eventually find each other in storybrooke again, Ingrid and her sisters their childhood ribbons, and worst of all, caused Regina to learn dark magic.