The original question is not about selling nucs. It is about using nuc boxes for the colony, (the brood and honey supers.) Seems like a precarious tower to manage, say four 5-frame deeps for brood alone, then who knows how many more honey supers on top of that in a strong flow.... Selling Nucs, the stack would never reach more than a couple high, then be sold. ..
I plan on keeping 2 body deep 5 frame nucs for the purpose of of overwintering and helping weaker colonies in the spring.5-frame nucs are terrific. Mostly I keep them stacked two boxes high and when customers come to pick up their nucs I transfer the bees to their boxes, the best 5-frames out of the ten available and most of the bees, then I just give what's left a new ripe queen cell, and soon they're going strong again.
They're good for many other purposes, as well. I really like how they work to correct colonies that are in need of new queens or even many of those who appear to be hopelessly queenless. Fabulous weak colony boosters.
More on the actual subject of this thread- during the honey flow I am continuously robbing combs of honey from the nucs, replacing them with foundationless frames. Though it may be very labor intensive, nucs can be used as honey producing colonies - this way they are also comb producing colonies.