I try and make some stuff but find some of the things I would like to make difficult as I do not have electricity to make them in my garage so have to use hand tools, I do use of a lot of kit that I had left over from when in the army (hell of a lot) and know how to repair it in the field, I make my own snares and sell them mainly to gamekeepers also make purse nets for ferreting and a few bits and pieces for fishing, I have a fishing rod that I have repaired more times than I can remember, I would say that most of my kit is made of modern materials.
Not much to add really except I prefer primative fire making methods, Flint and Steel and Bow Drill. BUT there's always a but , I stink at bowdrill I need lots more practise. Like you I shy away from the named gear as it's usually way over priced tat.