How much does the spaceship engine cost?

Excuse me, could you please clarify the specifics of the spaceship engine you're referring to? Are we discussing a cutting-edge ion thruster designed for interplanetary travel, or perhaps a more conventional chemical rocket engine? The cost can vary significantly depending on the technology, size, and intended use of the engine. Furthermore, if this is a proprietary or custom-built engine, the price could be significantly influenced by research and development costs. Could you provide any additional details to help me give a more accurate estimate?