That would usually be four or five frames with a queen and brood (eggs). A swarm might be more bees than a Nuc. A bee "package" costs about $150 and usually it is about $150, but you don't get a matched queen, instead it is more of an adopted queen.

But getting a swarm is probably just pretty fun if its your hobby. Plus it proves you have the genes of a thriving hive (they swarm because they run out of room typically), one that survived the winter, is local at least for a year, etc.