"Price" is what sorcery has done to you. It could be thought of as a payment to the infernal spirits, a sacrifice you've made, an injury or heartbreak, or just a personality flaw that's grown worse thanks to the new company you're keeping.

A quick way to think about your character's Price is to think of something that your character enjoys, and then figure out how the demons have tried to ruin or taint it. For example, a character who once had a storybook marriage might find that he's grown more Lecherous (-1 when dealing with women). A police officer who prided himself on being fair and patient, might become Spineless or perhaps Cruel after spending too much time around demons.

A "Price" is sort of like an anti-skill set. It applies to a class of situations, and it's inarguably you. "Walks with a Limp" could work; it's a little colorless as it stands, but it will make an active character's life difficult. "Has an old enemy" isn't a price--when things go wrong, your enemy's to blame not you. On the other hand, "Thoughtless," "Takes Things Too Far," or "Bears Crazy Grudges" might work as Prices, and these might create Old Enemes pretty quickly.