I'm not sure how much they cost where you are, but they were important for me because no one I know has dogs. I wanted him to be used to being around other dogs and people in a controlled setting. For me it was $99 (New Zealand dollars that is) for 3xhour long sessions over the course of 3 weeks.
The classes mostly involved each person keeping their puppy leashed and close to them while the instructor taught us a few things and shared some useful tips and ideologies for puppy raising. We'd practice simple commands, but it was all very casual and there wasn't much pressure or high expectations (it's a lot for a puppy to be taking in at the time). At the end the they could be let off to play, but would be split up into big pups and small pups. If some of the bigger pups were more shy, or gentle they could play with the small pup group too.
I think it's especially great for new owners, because of how overwhelming having a puppy is, and all of the information you need to take in to 'raise your dog right', but it can be good for more experienced owners too. I would probably do it again if I got another puppy in future.