A local pawnbroker or consignment shop would be my first stop - Empire Loan, on Washington, could easily be a good place to stop by if you want to compare it to the places at 333, which if I recall correctly is the diamond and jeweler's building, chock-full of buy/sell joints.

Your best price is probably going to come from finding someone to buy it directly, somewhere like Craigslist or Ebay, but that's going to require more time, effort, patience, and luck...