I'm not an "all college is worth it" type of person. When I first saw this subject line my reaction was "here we go, another middle age person wanting to wreck their finances to indulge a career change fantasy." But, after reading your details I think it potentially makes sense for you.
You're young, lots of career ahead of you, so the pay differential has enormous potential.
No kids. This is a big one, frees you up to focus on your education.
Your finances are healthy with positive NW and some savings.
Let's take your max pay at current degree ($90k) and then, to be conservative, assume the low end for NP ($120k). Tuition and opportunity cost (what you forego in earnings to get the degree) come to $280k. So the $30k pay differential will pay for the cost of the degree in about 9 years, less if/as NP pay increases (as little as 4 years at top pay).
So lots of factors in your favor, but does it make sense for you? It depends. You're 25, so if you go back to school for say 4 years then you will finish at 29, then you need to work ~9ish years before the degree pays off, so it probably pushes your FI date back a bit. I think the big question here is when do you plan or hope to FIRE? If you plan to work to, say, 40 or later then I think NP is a slamdunk. If you plan on FIRE earlier then I think it's much more iffy.
More importantly, you need to be brutally honest with yourself about the work and sacrifice involved. I have a BS Comp Sci and MS Engineering and MBA - I can't tell you how many people I encountered who assumed they could just coast through, as if showing up to class and doing a little homework would be sufficient. We all have a tendency to think we're above average and special, but these types of programs have a way of disabusing people of such nonsense. Programs like the one you're considering are designed to weed out the folks who don't put in the required effort. You should expect to have no real social life for the next 4 years, and your wife should understand and be okay with this as well. Your life will be completely booked and frantic, especially if you continue working part time: Wake up early, study, work, homework, class, study more, class, study more, more homework, late bedtime. Lather, rinse repeat...for 4 years. If you can, take summer session classes -- no point in wasting those months. You need to be willing to spend all day on the weekends studying, doing homework, preparing for tests. Your attitude should that you're on a singular mission to get through as strongly and as quickly as possible. So you need to ask yourself if you're willing to put yourself through the wringer.
