We spent nearly 30 years planning, designing and deploying this. I don't believe there's an agency anywhere that can effectively cost out a project of that scope given that entire new industries can rise and old ones fall in that time.

For perspective, $10 billion is like 1% of a single year budget in the US and I believe the estimate includes the entire lifetime operating cost of the instrument.

If it did in fact just "cost that much" I would probably "not be that bothered."