On nearly all worlds across the frontier, trade bazaars of the I.S.G.U.M (Inter Star Guilders United Merchants) could be found in dimly lit corridors and via ducts. In the outland systems these traders supplied all manner of vital goods and off-world amenities.
Under warrant of trade most local authorities were willing to ignore small level arms dealing in the effort to bolster their economy so long as no significant forbidden weaponry began appearing after their departures. Usually the best place to acquire any array of autos, blasters, pinners, cookers and many others. All at "fair market value" of course.
Expeditionary outfitters were a profitable resource for those intending to traverse the outlands where possessing the right equipment could be a matter of survival. Such vendors often brokered in information with local underworld sources of charts to supposed archaeo-tech hordes, rare element veins and hazardous places sane men should not tread.