Not sure if this is what you meant, but I'd hesitate to dismiss it as a purely philosophical question. For instance, the interaction between theorists and experimentalists has benefitted both many times over. Now, I don't know offhand if I'd want to spend $20 billion on a 100-km telescope... But I might be able to be convinced that it was desirable. :-)
A 100 km radio telescope could be built for $10. You need two antennas, any size, 100 km apart. They could be linked with anything, cell phones, for example. An old laptop would provide the software and data processing capability.
There have already been radio telescopes of 5000 km using off the shelf components to image the surface of Venus.
Not to say that a request for $20 billion is out of line, but it is extraordinary and will only populate Kant's 1755 nebular model with some more data.