I’ll be going off wikipedia info but it is what it is. There is some speculation that the Oreshnik is based off the Baluva which is around 30-40 million, so we will double that for the Oreshnik and assume something like 80 million. A one THAAD missile costs around 12.5 million with a battery holding 48 missiles on it. It would reasonably take around 36 missiles to intercept the Oreshnik’s different warheads assuming it’s possible at all. 12.5 x 36 = $450 million. The battery itself is 1 to 2 billion dollars. Granted, the US does have a much larger total GDP then Russia, but raw GDP doesn’t translate well very to warfighting capability and production, otherwise Russia wouldn’t even be a problem for NATO at all right now in the first place.