Prices vary depending on the model of your choice and how many features you are after. In general, you can buy a star projector for anywhere between $25 and $250. The cheaper models tend to be destined to be used as night lights and are generally inaccurate in their depiction of the night sky. More premium models like the Sega Toys Homestar Flux, however, are more expensive but offer you real-time, scientifically-accurate depictions of the night sky.