How much does it cost to build a velodrome?

Could you please elaborate on the various factors that contribute to the cost of building a velodrome? I'm curious to know if the size of the facility, the materials used, the location, and any specific design requirements significantly impact the overall budget. Additionally, I'd appreciate insights into the typical range of costs associated with constructing a velodrome, whether it's a small-scale project or a large-scale international venue. Furthermore, are there any significant differences in cost between indoor and outdoor velodromes? Your insights would be invaluable in understanding the financial aspects of such a construction project.