Nothing to do with “idle crafting times” at all, then.
I’ve literally been selling 300% profits and giving away coins because I can’t be bothered to click a queue thousands of times and cart hundreds of batches of stuff between machines when minting the raw stuff is micro-profits lol.
Ironically most of the people I see post about buying common materials are people saying they need more coins to be able to build due to limited playtime.