This really isn't hard to understand, it simply depends on your baseline. There is no cloudiness to it beyond your understanding of what is being stated.
If you are comparing the fuel economy of a Toyota Tundra and a Prius, does one consider the fuel economy to increase or decrease? Well if you are driving the Prius and looking at going to the Tundra, then the fuel economy decreases (lower MPG). If you drive the Tundra and are looking at going to the Prius, the fuel economy increases (greater MPG). Both are right.
Also, maybe this is lost on you, but the OP is asking about going from the .44 magnum to the .357, not the other way around. Those presenting the costs as a savings or decrease are actually presenting the figures consistent with the OP's question. By contrast, your insistance that we view the cost as an increase going from .357 to .44 is presenting the figures converse to the original question. So ask yourself, who is really spinning what?
If you are comparing the fuel economy of a Toyota Tundra and a Prius, does one consider the fuel economy to increase or decrease? Well if you are driving the Prius and looking at going to the Tundra, then the fuel economy decreases (lower MPG). If you drive the Tundra and are looking at going to the Prius, the fuel economy increases (greater MPG). Both are right.
Also, maybe this is lost on you, but the OP is asking about going from the .44 magnum to the .357, not the other way around. Those presenting the costs as a savings or decrease are actually presenting the figures consistent with the OP's question. By contrast, your insistance that we view the cost as an increase going from .357 to .44 is presenting the figures converse to the original question. So ask yourself, who is really spinning what?