Cost-effective is the best description. It doesn't have to be a totality. For total operation costs (training/missions/acquisition/maintenance/capabilites), the B-52 is cheaper by orders of magnitude.

The B-2 does have its place and is better suited for certain jobs, albeit at too high a cost. The B-21 is purported to lower that. We'll see.

Edit: Looks like current B-2 operational/maintenance costs are now down to only about 2x that of the B-52, which is an impressive reduction (no sarcasm).