Do you have a local sporting goods store that sells singles? That could keep you from buying so many. 4 boxes would last me 4 or 5 seasons.
I wanted a variety of different loads, as I still have to pattern them. The intial cost is what kills you when you must pattern them, which can involve shooting many as it is also a new gun. So I purchased both 3in. and 3.5 in. in a couple different shot sizes.
But yes, once I decide on the load that shoots the best, 1 box should be plenty for 1 year, as I only get a few turkey tags.