Okay! That is the Southern Cross. In those dimensions, it is properly a naval jack, although most people would call it the battle flag (which is, properly, square with a white trim). That makes it a bit harder to evaluate. As Nick said, with the zig-zag stitching, it is very late 19th century at best. But it could also have been made recently, too. That means we'd have to see it to zero in on a value, but to throw out general figures, from almost nothing (recent manufacture) to a couple of hundred dollars if it reaches back to the beginning of the 20th century. If it can be tied to a Confederate Veterans' group, with documentation, it could get a bit more.