Well for your example it is really better to just prefab 50 auto mines on earth ship em to mars then ship the minerals back EDIT: if ur just after resources just auto mine stuff.
Except that civilian shipping will actually generate wealth for both you and their company by moving colonists around. I've heard people recommend starting a colony on Mars even if there are no minerals for the sole reason to jump start the civilian sector.
Note that automines take twice as long to produce as their manned counterparts. So, while you'll certainly be building a significant number of automines to take advantage of uninhabitable, but resource rich worlds, realize that, in terms of upfront production costs, manned mines can produce the same amount of minerals at 0.5 accessibility as automines can produce at 1.
As far as moving construction factories, I'm the type that has a centralized industrial sector. Hell, the only non-mining industrial buildings I have that are currently not on earth are nine terraforming stations and a genetic engineering center (Found in ruins) on Titan and four ground control training facilities on Luna (Nice little "exploit" to take advantage of a smegty civilian governor that has a 30% training bonus. Required me to build a small orbital habitat, though, but it's still far cheaper than the equivalent increase in production through straight facility construction). Oh, and a level two sector command in the system next to Sol, but that's actually going to be my future industrial center (Once I vent 13atm worth of gasses). Nothing like 9mil duranium at 0.9. What's funny, though, is that that sector command has been constructed entirely by engineering companies. Currently taking a couple months under two years to build each level.