Mine isn't finicky about what brand of ammo I shoot. Any 180 grainers will work just fine. Sight in your gun 2" high at 100 yards and keep yourself a handfull of shells from that pack for hunting. Should you buy a few boxes, check out the lot numbers (usually inside of the flap) and try to get them all the same.
If you want to make yourself feel good with Premium bullets and prices, go right ahead...but the moose won't know the difference.
Whatever spot you end up picking, know the distances in that area. So if a moose comes out at a certain spot, you know exactly how far away it is and can make a decision to shoot or not. If you have a rangefinder and/or a topo map, you'll be ahead of the game. Also, know your bullet drop which you can obtain from any ballistics calculator or chart. Personally, I wouldn't shoot over 300 or so yards and make sure I have a good rest to shoot from.