The most effective weapon of the Afghanistan war was the 40 year old B-52H bombers. The B-52 entered service 50 years ago, and the current ones were the last built, in the early 1960s. Compared to more modern aircraft, the B-52 is simple. It's basically a transport for bombs. Its also cheap. The cost per flight hour (for maintenance and fuel), is $7,100. Hourly costs for the B-1B are $10,635, for the B-2 it's $13,538. But because of the special hangers and maintenance needed for the B-2, you either fly twice as many hours to come in from the American Midwest, or build those expensive hangers closer to the targets. So in the case of Afghanistan, the actual cost per B-2 sortie was twice the nominal cost because of the 32 hour missions. Not included in the above figures is the capital cost (amortizing construction and R&D), which is much lower for the B-52s and much higher for the B-2. Thus taking all costs into account (including different crew sizes), it would appear that the actual cost per flight hour is something like $8,000 for the B-52, $16,000 for the B-1B and $32,000 for the B-2. However, if you got the money, the important thing is getting the right bombs on the right targets. All three aircraft can do that, and all three can, with sufficient tanker support, fly from North America to any place on the planet.