Or why not have money sinks for:
1. Create extra clothing, facial, make-up and hairstyles at the avatar station.
2. Hull & Wing Variations at the ship paint station.
3. "Gate" keys that unlock gates to special raid or prospecting areas. (Keys are 1 time use).
It's too bad the devs do not have access to the source code, otherwise come cool idea would be:
1. Ship fuel. Sold by NPC's only. Less effecient reactors use more fuel.
2. Gambling Dens
3. Extra vault space