yes and no. Imagine they have 100 40k drones. Imagine, if a drone hits it will destroy $10mil in property. So your $100k or even $500k interceptor looks cheap.

However, they have 100 of them (so spend 4mil). so you might have to spend (if say 100k each). 10mil to protect your 10mil in property (and more if the interceptors cost more).

If on the other hand you can get the cost down to pennies (minus R&D costs), this is no longer part of the calculus.

Yes. To compare to alternative defenses.