Total of $ 83 billion was spent on creating, training and arming the ANA, roughly $ 4.8 billion per year. Since these funds were given by the American tax payers, these numbers are audited. Take at least ONE yearly audit (in reality there are multiple audits). Procurement, cost, quantities, destination is all tracked and accounted for. No one can just lie about the longest US military operation in history. This wasn't a small black ops!
The number provided by the Pentagon can't be wrong. I called certain things "exaggeration" as to me, majority of that equipment would've been brought home. But if it was left for ANA as stockpiles, than that's the truth. I guess these stockpiles did create and well equipped a new army overnight.