I have collected many things in my life. Baseball cards, World War 2 Rifles, Coins, Stamps, and many others. Trad bows is the ONLY thing I have ever collected that does not have a set Price Guide that comes out monthly or yearly. It is something that , I think, is lacking in the industry/hobby.
Because of that the only way to determine value is to track actual sales that occur and how much someone was willing to pay for a comparable bow. Many suggest looking at completed auctions on epay to see value. I think this is a good measure of what someone is willing to pay for a bow that they really want, but I think bows tend to sell for more on epay then they do on the classifieds here, or other archery related websites.
Just try to find some place where a similar bow actually sold and see what it sold for (this is what the traditional price guides for sports cards, coins, etc do.)
Then you have to keep in mind that things like holes, refinishing , etc affect the price. When someone asks "What is bow X worth" I think that all of us collectors come up with a price in our head, but who's to say than one persons opinion is betther than anothers. That leads to the age old answer "the bow is worth what someone is willing to pay for it."