A Assuming you’ve made a long-term, diligent effort to get work in your preferred field (which involves aggressive networking, initiating information interviews, proposing a volunteer internship, etc.), then holding out for such work may prove fruitless. It also may be unrealistic to expect comparable salaries in unrelated fields. Pay may be lower precisely because so many people have rushed in to do that line of work.
If you accept the current job offer, nothing stops you from continuing to network on the side. In fact, it’s easier to pursue a dream job when you’re comfortably ensconced in a well-paying position. And just because you lack interest in the job that’s available, that doesn’t mean you won’t develop more enthusiasm once you’re there.