Electrolyte additions are something that might not be worth buying in bulk individually unless you are a riding very many miles a year.

I buy maltodextrin from a homebrew supply since carbohydrate is the larger bulk of my hydration mix. I might could get it cheaper elsewhere, but this is inexpensive enough for me.... https://www.morebeer.com/products/maltodextrin.html

Depending on what you want, some of these are electrolytes..... https://www.morebeer.com/category/br...modifiers.html

But also just table salt along with some lite-salt from Walmart or the grocery store will probably give you what you need inexpensively for electrolytes.