I believe the TG moderators frown on folks putting value on bows.
Your best bet is to check the completed listings on that auction site, but like others will say..."it's worth what someone is willing to pay". That's kind of simplistic, but there is also some truth to it.
If interested in selling, put it in the classifieds at a price you come up with, and if it sells, that's what it's worth.
Your bow was one of the few target models that Bear introduced in the early 60's, along with the Tamerlane and Temunjin. Your bow was made in the 1970's.