As much as #1 might be disappointed, you need to make the choice that is best for you. I accepted and worked at a job and during my probationary period, got a better offer for significantly more money that was in the field I wanted to be in (the original job was in publishing, but the 2nd job was in educational publishing). I gave my notice and left. People weren't happy with me, but whatever. It was the right decision.

If you're more excited about #2, go for it.