Use the estimator tool at BB's website http://www.bestbuytradein.com/bb/QuoteCalculator.cfm?level=1&value=180 If the estimate is something you find worth it. Take it to a BB store for a final inspection and if you accept their offer (which can vary from the quote online based on their physical inspection of device) you can get a gift card for that price and then apply it to the price of a new iPod Touch.
----------ALWAYS check your purchased items for damage before leaving the store. If you never leave the store and check it in front of a employee it removes all doubt that you might have damaged the item.----------