Hello Nana,
What their thinking is that if there is water on the moon it can be used for two purposes.
first if they decide to put a manned base there if there is water to use it would greatly reduce costs of transporting enough to supply the base.
Second if they ever decide to actually go to Mars and they can stop along the way to pick up water it too would greatly reduce the cost of getting it out of our strong gravity.
Lots of money for what? I do not know.
Personally I think taxpayer funded “prospecting” is a fairly good use of money and its something our government has done to some extent all along.
That said, corporate space start up should be pretty much tax free for any company that actually gets there and shows that profit can be made.