Star base shipyards

From Starport: Galactic Empires

The four Starbases in the galaxy all have shipyards, the place where new spaceships can be bought. Since a character can only have one ship at a time, purchasing a new ship includes trading in your used ship. When trading in, you'll be credited for the base value of the ship, plus shields and cargo holds. Your scanners, primary weapon, and hardware items are kept and transfered to your new ship. The contents of your cargo holds is not included in the trade in value so it's advisable to empty cargo holds before trading in your vessel!

Hardware is also bought at the shipyards.