I hope you have ALOT of money!!!!!
Honestly, I would just take your time & look for good condition Bears, at affordable prices... Most, just need a good cleaning up. After all, they are 40-50 years old!!! Minor dings & scratches give character to the old Bears, and usualy, hardly noticeable. You could even take some of the "cheaper" priced ones you buy and try refinishing them yourself.
As some have suggested, pick a particular year, or maybe better, a particular model!!! I'm a big Grizzly fan!!! I have several years, and it's easy to see the differant changes in styling.
Good Luck with your future collection!!!!!