The upfront cost to fully maintain guitars yourself is too high for me. A good set of nut files and saws from stewmac is like $100. Then you have to get fret end files and all sorts of other tools too.
I mean like going to a Lutheiry school after my primary education. Musician's Institute in Hollywood has a Guitar Craft Academy. There's also a school in Arizona called Roberto Venn, which is a school purely for Luthiery.
Also I mean make guitars. My own designs and such, not just maintenance and repair.