What is my old raleigh bike worth?

heres the problem i dont know how old the bike is as i got it from a second hand store..but i do know its old and was told that it was a twin tube mixte and that i could get 300 or more for it.. but i really dont know.. its got i think there called cruise handlebars..but i really dont know anything other then that.. it says suntour on the derailer and stuff..please any help would be awsome..how much i could get of it or what year or kinda of raleigh it might be