Prosperous Hill VI was a bustling planet.
It not only featured varied industrial sectors, but also funneled in trade goods produced from the other planets in the inner system or transported over from other star systems in the region.
In turn, Prosperous Hill VI also shipped a lot of goods outwards. The PHTS constantly worked their cargo ships and transports to the bone due to the sheer amount of goods they had to cart back and forth.
In fact, some trading companies didn't even bother to go through this whole song and dance. A huge amount of aging and dubiously space worthy cargo haulers floated permanently in the outer system.
They acted as private warehouses that offered convenient storage space and transfer of goods to any trade vessels that happened to be in the vicinity. It was much cheaper and faster to hand over or receive goods this way, but only if the vessels in question arrived from the right star system.