> Do I need to accept everything else to get this service or can I just whitelist this line item?

It's a bundled deal, sorry. It's not just governments that avoid admin overheads - no auto insurance I know will let you pick which specific impacts to insure against a la carte, just to reduce your premiums.

Also, no 2 people will ever agree on the same government spend (to the nearest million), so I don't see the point of your exercise to personally quantify how ones tax dollars should be directed. The point of having a representative government is so that individual citizens don't need referendum on how much to pay for toilet paper at an USAF base in Japan, or disease reconnaissance in central Africa - but both things benefit US citizens (broadly speaking) and need to be done, so congress allocates the money.