You’re an explorer, your goal is to visit as many systems as possible and don’t want to build a heavy base to make money with your numerous biodomes ? You can get between 2 and 4M benefits by warp if you have a big ship and follow a “logical” trade route.
You can still stock pile a rare resource, (build a base on that planet) and go to different systems selling that resource, it worked for me and its how I got 8 million units really fast
Trade routes are more for the trade item than ressources or crafted. Of course we’re supposed to follow different loops, not staying in the same 4 systems. If we’re in a type 1 system, we explore it/make missions, buy the best trade item as possible, move to a type 2, sale items, explore, buy etc… and after, we need a different type 1.
In that way, with mediums 3 planets systems, with just trading and scaning it’s not difficult to get 15M/jump. If you add well paid missions (250k and more) and the ones which give you ressources for the 18M items, credits are growing fast.