That makes no sense though, because at least during the first 12 hours of the game it is around 5 times more efficient to just grind raw materials, sell them raw, buy the blocks you need and repeat, and even after a long time it is still probably 1.5-2x more efficient because any time spent making blocks is time wasted that you could be either mining more raw mats, shuttling them to a shop, or something else productive. I looked at the numbers for almost every block, typically it is 5-100 credits more expensive overall to mine raw minerals, produce blocks with them, and just use the blocks, than it is to sell all the raw mats and just buy the blocks off the store. Given that factories operate on a loss as well as take a long time at low levels, I can't think of any logical reason to use them besides shops running out of certain blocks.