I think Bachmann figures a reasonable selling price for their product, then adds a substantial amount to that to create MSRP. It seems to be a way to capture the part of the "Christmas train" market that does not have space for a Lionel, but at Lionel prices. Prices then fall until they reach a level reflective of their fidelity to prototype and level of detail.
I recently saw some of the Bachmann N scale "Budd" (in fact, only the coach is a model of an actual prototype) cars, advertised at prices 1/3 of MSRP.