The somewhat tricky part of this is the moose part. What is adequate for that will be overkill for a deer. To walk the line but be successful with moose I personally would say no less than a .300 Win Mag.

If your looking for new then the there is a ton of options, if you looking for used then it opens up even more. I've seen some 325 WSM guns go for great prices, overkill for deer but would be a nice round for moose.