As stated above there are way to many variables, however (second year newbie) I kept 5 supers on hand per hive. Thats for a new hive by the way. right from a package. That allowed me to use a couple extra for hive bodys, becuse I use mediums. then a couple left over for stores, if I needed them. And you usually need an empty one for putting around the inside feeders, if you decide to use that method. No one can give you a diffenitave answer but kept around a few extras. It wont hurt to have extra's and like stated above, if you need them, you got them. You could have a bounty of food sources and not even know it.
what I found last year, my first year, I used the extra's, and only had a couple left overs. This year I am ordering more than I will use but better to err on the safe side. dont know if this helps and others may disagree, but heck thats what its about. agreeing to disagree.