I checked out my 1971 Bear Temujin last year. I believe if you just type in Bear Archery you will get a list of sites. one of them (I can not remember which) has a listing of serial numbers and dates. Also a lot of bears can be dated by the medallion in the riser. and there is info on that.
The best way I found to get a value is to post in the classifieds on several archery sites and see what happens. Archery Talk is a good one.

I paid $200 for my Temujin which is a lefty target bow two years ago.