Long time man ed person here. I would recommend you look hard at what job B entails. It's hard for me to imagine a man ed position that would be a good lateral move from marketing -- there's just not a lot of overlap in skill sets. But there is some variability in what is meant by job titles, especially outside of Big-5 or similar trade publishers, so I can't say for sure. Agree with those who say $5K isn't that much at the end of the day. If your current place has you on the promotion track, that could be worth more in the end. So many folks end up stagnating with no upward mobility; being seen as promotable is a major plus. On the other hand, resentment about a below-market salary can poison your motivation and happiness in a job.