Self satisfaction
I try not to think about the cost per fly. There's nothing more satisfying than to catch a fish on a fly I personally tied. I don't need to have materials to tie every fly known to man, just enough to tie the flies that work in this area of New England. One that works for me is the Wooly Bugger and it's so easy to tie (at least I think so.) I've also done a few variations from the "book recipe" by adding crystal flash into the tail. Some have bead heads while others have non-lead wrap under the body.
I like to spend time tying the flies rather than to analyze how much it will cost per fly (or by the pound - I have yet to find a shop selling by the pound!)
I do find it humorous to see what a fellow fisherman will do to kill time on a bad fishing day (if there's such a thing!) LOL
Enjoy the day!
D.A.Flymann
Eventually, all things merge into one, and a river runs through it. (from A River Runs Through It)