Okay ships use wilderness refueling to save credits. However, their crews do have money to spend. While their captain won't want to head for the mainworld, which has no market for his cargo, the crew still wants some leave. Even a few hours. Smart captains will give a little. Forward thinking world governments will see a way to make some bucks off passing ships.
Presenting Last Chance Outposts. Also known as side ports, gas 'n goes and a variety of less wholesome names.
Many worlds with a C starport or worse establish a space station near the inner gas giant. Sometimes it's an orbiting base. Other worlds use one or more large insystem craft, the better to meet captains eager to make their schedule. The mobile outposts carry a variety of merchandise, spares, filters, vacc suits, ship's locker items and personal weapons.
A number of outposts have very basic repair services have basic repair stations and a large EVA crew to perform them for ships that have been damaged during refueling. Without exception such repairs always take at least a few hours allowing the ship's crew to partake of the other outpost services.
An outpost will have a restaurant of some type. They vary in quality though most at least serve fresh food. After all the crew can get microwaved packaged crap onboard for nothing. Other shops will sell local goods such as luxury items or handcrafts all at steep mark up.
There is usually a compartment or several reserved for various illicit activities. These red lit corridors have almost anything you could imagine for sale or rent though what's illicit varies wildly from world to world. You might wind up in a coffee bar or out of uniform. Note this section is not openly advertised and requires some Streetwise or Steward skill to learn about and enter (as well as credits).
Finally each outpost has a cargo hold filled with a variety of items for speculation. A lot of haggling happens here. A great many items are organic in nature. Dumping food cargos due to spoilage, mold or fungal infection is common. So common that no one really looks into it. Some dumped cargoes find their way to an outpost where they can be bartered for other organics leaving no paper trail for the revenue services to follow and tax.
Other cargos can find their way to the cargo hole depending on how believable a story the captain can come up with. You might get away with saying you dumped some pcs with viruses downloaded from the factory that weren't worth debugging for example or saying you got swindled on some goods and threw them out the airlock ("What the hell are 'Bollex' wrist chronometers?!")
Some outposts are owned outright by the mainworld governments. The mobile outposts are often franchise owners moving from system to system or in many cases squatters on the gas giants of worlds that haven't the means of chasing them off or assuring they get a cut of the profits.
Another lucrative role for these entrepreneurs is as camp followers, tagging along behind a large mercenary group or an invasion force catering to the military's whims. War can be a cash cow no matter who wins.