mcjaco,
Well, I was including the distributors 10-15% cut, but you are right, typically, I believe the mfg gets about 40% of MSRP. Even using old tooling, I wonder how much money these projects net them. I do believe that most MRR mfgs do it more for love of the hobby than to make money, and yet, we bash and bash and bash because they aren't making one model that each or any of us dearly need.
Frankly, I have been surprised at how diverse the market has become in terms of prototypes. I mean' Kato's full passenger trains? Whoever dreamed that? But, guessing the sales aren't there for a limited prototype loco doesn't make the folks at Walthers villains. Nor does internet clamor make for a detailed marketing study. I recall Paul Graf telling me at the NTS one year that all they heard for years was "Make the big Alcos" or "Make a U Boat" and when they made them, they weren't great sellers.
Short version, I think its probably what it ought to be, with the mfgs mostly making the right product decisions most of the time. Of course, there are a few flubs, like the double products, but in all, if an Alco S2 can sell, they know it and make it, etc.