You might want to see what others are asking for similar items on ebay, rubylane, firstdibs, etc. Bare in mind that unless the site also provides information about "sold" pieces, you're looking at what people are asking for that piece rather than what people are willing to pay for it. BTW "what it's worth" and what you can sell it for are two different things. How you sell it makes a huge difference in what you get. If you sell it to pawn shop, jeweler, or someone else who will re-sell it, you'll probably get far less than if you try to sell it yourself - but you will likely have that smaller amount of money in your pocket far faster than if you go the do-it-yourself route.