Pace, If you can't afford the 300, don't worry about it. As much as you say you would use it, I wold say pass on it. Your '06 will handle moose and bear no problem.
I have a 300 WM and I like it. But then again, I don't have a '06 (I must be un-American). My most used rifle is my .270, followed by my 7mm-08 then the 45-70. The only time the 300 WM comes out is when I think I may get a shot in the 250 - 300 yard range. Like DM says 300 yds is my max. I would ever consider shooting at any critter except maybe a varmint.
Your 06 is fine. Use your own judgement.