Considering that we're not dumping "billions" into it at this time--it's actually a bit less than a billion--yes.
Can you afford it?
The entire infrastructure? No.
Can I afford a nuclear bomb?
Yes.
Particularly if I only intend to own it long enough to get it to its DGZ (designated ground zero) and detonate it.
It'd make for a REAL short war. If we had had that kind of a policy from the beginning... we would probably still have two really tall office towers standing in New York.