3 Juno is a special asteroid being one of the first ever discovered over 200 years ago, and one of the largest in the Main Asteroid Belt. It is so large in fact that it could easily be used as a station for human and robotic mining operations, which itself could be its primary worth. Juno is an S type asteroid, suggesting silicon compounds and a primarily stony composition.
A 10 square mile claim would be enough for basic mining operations and local support structure. Hypothetical estimated value in 2017 USD $1 trillion. The number of available claims is limited to 7,350.
Image Credit: NASA / JPL-Caltech / Harvard-Smithsonian Center for Astrophysics