Gunbroker.com lists Ithaca M66 Super Single 12-gauge 3-inch chamber shotguns for $50 to $125. These shotguns normally retail for $100 to $125 in good condition. They retail for as cheap as $50 in poor condition.
From 1963 through 1978, the M66 Super Single 12-gauge with a 3-inch chamber was manufactured and marketed for roughly $30 in its early years. It had an unusually lever-activated, break-open mechanism for shotguns.
The year of manufacturing for a certain M66 Super Single can be identified by comparing the serial number to a PDF document on the Ithaca Gun Company’s website that lists serial ranges by year.