You could always make it a huge mistake on your character's part, something they are trying to live down or make up for moving forward.
You said you are a Changeling, so a complicated home life is likely. How old is your character? I could see you having a Lea in your life and accidentally leading a group of kids to the slaughter. Say a very young you was a run-away that had a run-in with a Fae, and against the odds made a bargain that came out OK. Maybe you had leverage you didnt realize (casual Iron, sudden emergence of your own fae powers, etc), or maybe they know your Fae parent (for better or worse) or had some preexisting bargain that imposed limits (may they are your godparent, maybe they have a non-aggression pact with your fae parent, etc). Whatever the details, your first experience was abnormally benign, leading you to a false sense of safety.
Then when your Crew/Gang/Posse are in trouble, you go tot he nice magic person that helped you before, and the next thing you know you sold the Lives/souls/freedom/futures/dreams/memories/strength/whatever of those who had trusted you to lead them and keep them safe. As their entrusted and empowered leader, you'd have more metaphysical right to bargain on their behalf than otherwise. The Price should probably be equivalent and relevant to the sort of group it was and what they Entrusted (capital 'E') to you as their leader. Maybe you promised to lead them to a better life and brighter future, and they all loose their Dreams and all motivation; maybe the streets were rough as hell and they trusted you to simply keep them alive day to day, then you'd have their very Lives in your hands. Maybe most of them were addicts that you kept from falling off the deep end of addiction and were keeping their identities from unraveling, so they loose their Selves and go comatose.
Whatever the case, you made one defining mistake in paying for Power with People, and now are on a redemption path trying to make it worth while, or maybe get them fixed or free or something. It would make for a hell of an interesting dynamic with your patron.