How much did sputnik 2 cost to make?

The cost of building Sputnik 2, the second spacecraft launched into Earth's orbit by the Soviet Union in 1957, was estimated to be around 7.5 million rubles at that time. Adjusted for inflation, this would be approximately $6.5 million USD in today's currency. The spacecraft was significantly more complex and expensive than its predecessor, Sputnik 1, due to the addition of a life-support system for the dog Laika, who became the first living being to orbit the Earth.