The Amarillo Design Bureau (of Federation Space, Star Fleet Battles, etc.) have got an interesting product up on DrivethruRPG, "Merchants of the Federation", a PDF prototype game where two to five players can start trading on a newly opened Federation frontier. Make money, upgrade your ships and plant colonies, but beware the nearby Klingons... https://www.drivethrurpg.com/product/285170/Merchants-of-the-Federation It uses the ADB ships, but you could easily put in various sizes of merchant vessel to suit your own Star Trek universe. If there is enough interest they'll produce a boxed version. This PDF version is cheap and seems like it'll be worth trying out.