My first nuc purchased (and first hive) was a 3 framer. He had me put a deposit of $20 down for the nuc box he made, but told me I could just keep it, and I did.
Every other nuc I bout had 4 frames of brood in various stages of development and one frame of pollen/honey. They all recomended/needed to be transfered to 10 frames in the next day or two.
My last nuc was 2 frames of brood, one frame food, and two frames of half drawn out comb. I notified the seller that it was on the weak side in comparison to all the other nucs I got. Not as an insult, or demanding a refund or anything, but more as a feedback so he knew where he stood in comparison to competition. He offered a partial refund (which I rejected, thankfully), but explained that he talked to a few commercialists in the area and they claimed they packed all their nucs with 2 frames of brood, one frame food, one frame drawn comb, and one frame foundation only. He thought two frames of partially drawn was better than one frame drawn and one frame foundation. I told him if I bought a five frame nuc, I expect five frames of something. If they tried to sell me a five frame nuc and one was foundation, I would request 1/5th my money back.
But that is just my experiences. As I explained to the seller, these may not be the industry standard, just what I've seen.