Its original , my cousin was a collecter and left me a few some i gave away and some i kept , i really don't know how much its worth but i do remember that he bought it from a comic book store in nyc when it first came out..
Adventures of Superman #500. You can see what it looks like outside the bag here: http://www.comicspriceguide.com/p-issues.aspx?P1ILpc3P7Cq62atm%2bjzMkAKKAGj7HZXczMcOiwQu%2fps%3d