In hindsight the much better play would have been to just pay the Taliban 50 billion to give up Bin Laden. There's no good option there and ever has been.
My father told me that a representative stated on the floor of Congress in 1969 that the United States could pay every man, woman and child ten thousand dollars a year not to fight and save money. I've never found the quote. Rough napkin calcs - $843b in 2017 dollars, 17 year war, 37 million people in North Vietnam in 1965 has it at closer to $1200 a year.
Lol because when the "advisors" the CIA inserts into Saigon stir shit up to the point of Agent Orange, the Agent Orange comes out of someone else's budget. The initial calcs on the cost of Afghanistan were "take bin Laden" followed by "hearts and minds won" followed by "mission accomplished. If you look at SOCOM's history in Afghanistan you'd think we left in 2004.