Some great advice I'm reading here.
I think if you really want a Magnum and think some future hunts can justify one I would go with the 7mm Remington Magnum. It will easy kill elk or moose,nothing more is needed,and the ammo is much cheaper and easier to find. If you happen to pop into a small town,population 1800,on your big hunt for more ammo,don't expect to find Weatherby ammo.For instance here in northern Canada there are only a few stores that carry it,but you can get 7mm ammo anywhere.
It would be really nice if you could try some shooting with an example of each,that might "seal the deal".
Moose calling can get confusing to some, but cow calling is your main tool when moose hunting. If you go out and buy moose calls I would say you're wasting your money unless it is the birch bark cone. I find most store bought moose calls sounding worse than puffing a grunt your hands to make the call. You can roll up a piece of birch bark in a cone shape to use as a call and spend your money on a video that teaches you the basics of a cow call. A milk jug or a coffee can with a hole and a rope...