You've already got the MS, I wouldn't bother with more tech stuff unless it would involve a lot of hands on work with perhaps mechanical engineering and 3d printing, CAD/CAM stuff, etc. Think of the parts you could make
I'd be tempted to maybe just do a bunch of gen-eds in history, maybe anthropology, earth/space science, etc.
I get free classes at the college I work for as well, my daughter's AA is costing me about $200 per term and I got my batchelors for about $1k out of pocket. Our benefit only covers tuition and lab fees - that whole "student life and activities fees" etc aren't covered... Since we are a "not legally allowed to be called a community college because we offer a few 4 year tech degrees", I can also go to the "other school in town" (UF) for almost free as well (and UF folks can come to SF....), and my dependents at about half price, though they may have some benefit from my dad who taught there from the early 60s until he died in '94