Let’s just get it out of the way, building your own pedals will probably never be cheaper than just buying them.
That is, unless you plan on building a lot of pedals. Economies of scale will likely never work in your favour, but if you stick with the hobby for a while I suspect you start to build up a supply of various components and tools, to the point where you can experiment with new builds with almost no additional investment.
Then it might just start to make economic sense…
Then again, I guess very few builders are into this stuff for pure economic reasons. I know I’m not. I do this (or I want to do this) simply because its fun. And educational.
My goal is to get to a level where I can experiment with effects that I dream up myself. I already have several ideas that I’ve been carrying around since I got into modular synthesis.
Hopefully this time around I’ll actually realise at least some of them!