[Need advice] Attend grad school full time or going part time with full time job

Hi guys,

I am debating whether I should quit my job and pursue a MA in financial economics full time or if I should work full time and go to grad school part time.
If I go full time the master's degree is about $26k not including living expenses and would take about 1.5 - 2 years. While if I go part time it would be free, but it would take about 2.5 years to 3 years.
The biggest advantage I have is that I currently work as a fiscal assistant at an university so the master's degree would be 100% free. This would also allow me to keep my standard of living and pay off some student loans. The job is also flexible and would allow me to focus on school.
My biggest worried is that I know I want to eventually work in the investment field and if I work full time I won't have time to do any internships (i.e. financial analyst, portfolio analyst, investment analyst, credit analyst, etc.) So I am unsure of how hard it would be to make the jump from the public sector to the private sector with no experience. I know that at my current job I could possibly move up to a more financial manager position, but again I am unsure how this would help me later down the road.