I have to say I do think there would be significant financial gain from going from a LPN to a RN. True, not much difference between pay of 2 yr RN to 4 yr RN, but definitely a signficant difference between LPN to RN (regardless of 2 yr vs 4 yr status, especially in the long run.) There are often fast track programs where you can do a LNP to BSN. Have you looked into see see if there are any of these in your area, or on-line? A lot of health care places (hosp and LTC facilities) in my area offer partial tuition reimbursement to further your education. Is this someting your current employer offers?
I started out as a 2 yr RN, took a few yrs before going back for my BSN and eventually my MSN to become a NP. Essentially, worked full time all the way through with No student loans until my last 3 semesters of NP program. By then I was doing clinicals half-time and working half time, and I was also a single mom and sole provider with two kids, hence, the loans. It was hard. One thing that got me through was knowing so many of my cohorts were in similar situation of being adults with other responsibilites-relationships, kids, mortgages, jobs.