You just select what you wanna craft in a Menu and it will tell you how much it costs and such. If you have seen the Resource Complexity part of the Game Ideas Page (Gameplans Page has become more of a TODO list format) then you pretty much know how the Recipes will just require more specific Stuff the harder it gets.
The easiest Difficulty is just “every Recipe just crafts with Money as ingredient” (in which case instead of crafting it would be more of shopping) while in the higher ones you have to use specific ingredients such as “X conductive metal, Y normal metal and Z precious metal” to craft something (Material Names are RNG so I wont just say Copper, Iron, Gold).
Ofcourse with the hardest one you need to use a lot of inbetween steps, though I would make it possible to do some steps recursively just like how Factorio Handcrafting works.
I still dont know how I am gonna handle Stone and Wood with the System, they might become separate Resources just to prevent things from being too easy. All in all I dont know if i keep the exact Resource Tier Layout that I made up on that Page.
Hehe, but I wont announce massive Details to the Game, that would be a way too huge wall of text. XD