Quin

Quin is the unit of currency used throughout HILT, though its value fluctuates wildly. Especially when humanity begins spreading throughout the galaxy, a quin has no consistent value from planet to planet, hence allowing someone to, say, sell a bottle of wine on one planet for 100 quin, only to then use that same 100 quin to buy a spaceship on another planet.

Clever people can use this to their advantage. Dumb people get frequently suckered in to giving away their life savings on stupid things. Much like tourists.