in techs tree, let there be a button (perhaps unlocked by hardened level) where we can buy the tech directly from market values of materials needed.

Yeah, that would be pretty cool.

If i remember correctly, it has already been suggested several times.
With the answer usually being either "uservoice" or "is covered by auto buy tech + auto market".

But having this as a button (instead of some shitty combo of auto advancements) would be really nice!