As many have stated here, Moose are just not that tough to kill.
They are not made of Kevlar. They will let you get quite close.
I have been hunting moose for over 40 years. In that time I have taken them with (or have seen, first hand, them taken with) 243, 270, 7.08, 30.30, 303 Brit, 308, 30.06 and even one guy I hunted with who used a lever action 45 colt and took down a huge bull with it.
Note "no magnums" in that list - not that I'm saying not to use a magnum, just my hunting bunch never saw the need.
I personally hunt (now) with a 7.08, formerly 30.06
So unless you are the type that will shoot at a spec on the horizon at 450 yards you can go with the "even bubba's guns at the corner of middle and nowhere has ammo on the shelf" - read 270, 308 or 30.06 - and it won't command a premium price. Put any one of them through the boiler room and Bullwinkle is going to go down.
And you know, despite all the advice and glossy ad's, moose do fall down when you shoot them with a 303 Brit 180 grain soft point - you don't need bonded, mono's etc BUT you "can use them and they work well". If you feel more comfortable using a premium bullet then you will confidence when you pull the trigger which generally means you will shoot "better". And ultimately, the box of shells you take on the hunting trip will be the "cheapest part of a moose hunting trip" so waffling over spending 50 bucks instead of 30 bucks for 20 rounds is kinda foolish when you are feeding them to hundreds of dollars of gun/glass and spent maybe a couple hundred bucks in gas to drive to where you are hunting - took a week off work and are packing in a couple grand worth of gear besides your rifle.
(Ok, I shoot Swift A-Frames for moose even though I know they will go down with a Core-Lokt, which I used to shoot before the A-Frames came out in the 1980's - they don't end up any "deader" but they do tend to go down quicker - boom, wobble, down)