Browning auto 5 20 ga. worth?

Buddy is selling a browning auto 5 20 ga. Vented rib. made in Japan. "light twenty". Anyone know what it's worth? I do not know barrel length. I have the 12 ga version that was handed down to me so i do not have a ballpark number. My 12 ga was made in Belgium. If i was to guess i would say 750 range. any ideas?

 

From what I understand it depends on the year. If its made in Belgium the value is higher than that of the Japanese made steel. Their is a newspaper-like catalog called the Gun List (I think) that can be found at major bookstores, or perhaps online. Also, call a gun shop, they have one of those big books on values.