No it wasn't the money in the end. When I first told them about my new offer, they came back with a 20k raise, and I was basically shocked. They said they really didn't want me to leave.
That's why I feel bad, because aside from the money, the new firm is much more recognized in my field, so it would be much easier to advance my career. That's why I feel bad, because it's something they can never match.