Please let me relate a personal story that is similar to your situation:
Many years back I was about 4 years out of college. I had worked for about a year and a half at a company where the work wasn't that interesting to me. Then I went to a place which was much more interesting. I had left the previous company on good terms and even did a few small favors for them over the next several months when they needed help. After being in the new place for 10 to 11 months, the old place offered me a 25% raise to go back to work for them. I wasn't interested in returning, but tried to use this offer as leverage to get a raise out of my then current employer. My manager passed this up to his boss who said something like "We can't match 25%, but we can give you 11%. However, since you're close to your review, you'll have to wait a couple months until that process is complete." She also assured me that with her approval this would go through. I liked the newer work enough that I accepted this (better benefits helped also) and turned down the offer from my old company. On the day my first paycheck with the 11% raise was supposed to arrive I got called into my manager's boss' office; the story now was "I'm really sorry, but my manager wouldn't approve your 11% raise, we can only give you a 5% raise." Knowing I'd burned the bridge with the old company, I started looking for a new job and started one about six weeks later, having received 3 job offers; however, none of them matched the salary I would have received if I'd taken the offer from my old company. This probably won't happen in your case, but it is in the realm of possibility.
Without explicitly thinking about it, many people could make more money by working in a different industry (e.g. finance vs. science), but choose what interests them. You have to decide if the interesting work is worth more than money to you, but also balance that against your future ability to provide for yourself and any family you may have (or gain), the lifestyle you want to live, your ability to retire early, etc.
If it were me now, I'd probably take that $50K raise and see how things work out at the new place. Maybe it will turn out to be better than you think. If not, in a year or two you can hunt for a new job, somewhat richer, and (presumably, since we don't know if $50K would double your salary or just be a 5% raise or what) with the potential to command a salary much higher than you make now. Maybe you can even return to the current company with a higher salary.
And yes, I realize I'm answering this a couple months after the question was asked, so the OP probably has settled things one way or the other, but maybe this will help someone in the future.