I am in medical device regulatory affairs. I do not have an MS and wouldn't suggest that you pursue the degree if you have to pay for it yourself.
It is true that you will learn the basics. However, it is absolutely true that if you have an MS in regulatory and no other regulatory experience, you will still come in at an entry level because as BevD said, experience is everything. Some of the worst RA people I know (as in, got fired because they were not good at their job) had an MS.
I have also known many people who came into RA from very different fields (electrical engineering, chemistry, business, physical therapy, political science, industrial engineering....) and were successful.
QC and manufacturing are relevant enough that you could transition into the regulatory side. I'd suggest looking at roles at a large company where internal mobility is possible. There are also many contracting/consulting firms that staff for regulatory contract roles. If you are willing to do some boring contract work for a while, you can start out there to gain some experience and then (ideally) move into a full time role.
I would also suggest you do as much supplemental cheap education as you can through RAPS, Emergo, RQM, Coursera, etc.... there are many places that do free or inexpensive webinars and training programs. I wouldn't put these on your resume, but if/when you do get into a regulatory role, getting that foundational knowledge will help you to move up faster and be better at your job. It will also help you communicate why your existing skills are transferrable to regulatory affairs.
