PC for Masters Degree.

This is crazy, and I cant believe I am trying this but...

First, let me say this. I am a husband and father of 3 with 2 jobs and a recent graduate with a degree in Computer Science. I want to go back to school and get my Masters Degree in Cyber Security but I have already incurred so much debt getting my Bachelors Degree online and my old PC just wont cut it. While I have found a great online program and I am working on getting scholarships, I will still need to fund the remainder with student loans and I would like to avoid spending any portion of that in a reliable PC. I want to build this PC myself so I can ensure it can be upgraded in the future (with my own funds). Thanks in advance.