This is hilariously cherry-picked. THAAD is extremely expensive if that's the case. Wikipedia says you can get a Patriot for just $4M. Also SLBM's as actually deployed aren't using maximum MIRV counts, both for treaty and role reasons. Wikipedia says 4 RV's on average for Trident, FWIW. But the big whopper is that you're forgetting to account for the
$4B SUBMARINE (just $200M per missile though) required to deploy those missiles in their cost!
Good job though. Honestly the numbers are closer than I'd have expected. But ICBMs remain more expensive.