The cost of a B-61 nuclear gravity bomb is only $28 million (2012). There are approximately 400, of which 100 were moved to Europe in 2022. They can only be launched by an F-18 or F-35 with a special armament control package (not included in the $28 million).
$28 million gets you spin rocket motors that improve accuracy to within 10 meters, and internal and celestial guidance. The yield is variable ("dial-a-yield") (10-340kt) to allow selecting the amount of tritium for the explosion.
The cost for an F-22 is $191 million (2023). A B-2 is $2 billion.