B-52 is much older, less maneuverability/speed and needs to focus on the nuke mission. B-2 is much more expensive and a national asset in short supply. When taken as cost/weapon dropped the B-1 actually has one of the lower costs (6-9 hours of loiter time and 24 JDAMs=8-ship of F-16s plus a lot of tankers).
The B-1 may be faster but with it's size and where it operates it wold present a huge target for any credible IADS, not much different than the B-52. As for you assertion that the B-1 is cheaper I seriously doubt it if you look at the total maintenance and other unique lifecycle costs coupled with it's atrocious mission availability that it is cheaper. Plus, the F-16 can fight back while the B-1 can only turn and run.
This is my take on the B-1 as well; given the similarity in payload capacity between the B-1 and the B-52, I would have figured the B-1 would be given preference over the B-52. JMHO.
The B-52 has almost twice the availability for half the cost as well as the flexibility of the nuke mission, not a very hard choice at all.
I'm no anthropologist, but it seems giving the bombing missions to the bombers (B-52), not the fighters (F-16), would be more cost effective.
Depends on how much it costs to get a bomber in the air and keep it in the fleet and the B-1's are pretty expensive.
I'm under the impression many Bone's were mothballed only to be brought back out some years ago.
They mothballed 1/3 of the 99/100 aircraft fleet a few years ago, they might have pulled out one or two to replace the ones they have lost but the rest are still in the boneyard.
Saw one taxiing out at Al Udeid today - even thru the shimmering heat, it's a mean looking aircraft! I find the proposal very credible - after all, the AF has mortgaged just about every other platform in their inventory for the F-22, so why not sacrifice a few more? Park them next to the EF-111s at Davis-Monthan...
I thought the Intruder and Prowler proved that looks aren't everything.

And it's not the F-22 anymore, it's the F-35 now!