I hope you're not dreaming of retiring to a desert island with the proceeds!
That is quite the conglomeration! Appears your grandfather pieced together 4 machines and managed to run them all off one motor. It seems that both the scroll saw and the table saw have Duro badges. Can the table tilt on the table saw to do beveled cuts? Is the lathe marked Duro as well? I take it that is a disc sander sitting on the lathe? Also Duro? It comes off, right?
I hope I'm not dashing your expectations but Duro was not a high-end manufacturer. As pictured, I think if you got $100 that would be a lot. Frankly, very few woodworkers would have much interest in the pieces or the whole thing. Maybe there is somebody out there who collects Duro stuff. Maybe?
I've been wrong before though. (Then I realized I was mistaken about being wrong!)
Craig