I totally agree with Roseary. You have to remember that when you go into these places such as PetSmart and Petco, they are offering BASIC obedience and socialization, both being incredibly important.
Is it a money waster? If your friend does not follow through with the at home reinforcement and exercises then it would be an absolute waste of time and money. I have yet to hear anything negative about these classes unless one goes in with extraordinarily high expectations.
The socialization experience for the pet alone is priceless. Pair the social aspect and basic commands and you have the making of a fine companion. There is nothing worse that knowing that when company comes to your home, you have to put your dogs up because they cannot behave in an acceptable manner.
More importantly, a dog who has not been socialized properly with other dogs tends to be more aggressive. I am dealing with this issue right now. Quick synopsis..German Shep, no socialization, attacks other dogs, killed one, highly aggressive, ignorant owner....ugh. Mind you, this is NOT my dog 
| 
