You want to buy a used bow (at least that is the hypothetical basis for your question)?

It is really hard to say. My mathews dealer will put me in a new mathews if the old one is in good condition for about 150-200 US dollars, that means the second hand person isn't getting much of a deal, but he has sold bows of mine that are up to 3 years old on that basis, and in comp colours (he resprays). He sell new bows at full price, but it is worth it to me since he can flip the subsequent bows for much less than I can get in and out for. For a while there he could do just as good a job on Hoyt, and he could do a sort of a job on HCA. He has gone mostly totally Mathews in recent years.

If the dealer isn't that agressive, and the brand or model isn't that good, then the price you get is low. I couldn't scare up 150-200 Canadian even for a new out of the box Alphatech last year. The dealers told me they had simmilar bows on the wall for 300 Canadian and they wouldn't move out the store, people who wanted a big name bow wanted the new model. The Alpha is an old model bow, but it wouldn't have matered whether I was talking my virtualy new Feathermax. These guys just haven't put the effort into a secondary market, so they don't have one.

I think ebay is a great place to sell, but a risky place to buy, for this kind of stuff. Last year I saw second hand stuff on ebay sell for more than it could be purchased for new. That is to say below the MSRP, but above what the discounters would sell for. This happened more than once. For that you take the risk of being DK'd and of the bow having problems.