I charge for my electronic repair work and don't mind helping one of my customers out. But I draw the line at helping somebody else charging for work in the same line. It is not hard to tell which is which....my customers ask different questions than other repairers do.
Other repairers can do what I did, read, read, read and experiment endlessly, hopefully not on a customer's item.
Also for doing e-books which I do for sheer amusement, I gladly study what someone else had done in the thousands of books in the MR library and modify it to fit my particular situation. Also most things can be converted to HTML which Calibre or Sigil will accept.