Well, the truth is, he is not supposed to be selling the episodes because they weren't his to begin with. They are all the properties of Sesame Workshop, and if the user does have the copies, he obtained them illegally. In fact, if he does obtain the episodes, he is not supposed to share them with anyone else. Uploading episodes is piracy, and it's illegal. If the police probe the user's Google Drive, they will likely delete every episode he uploaded, and likely arrest him for piracy, or make him pay a stiff fine. So either way, you will not be getting the episodes no matter how much you desperately want them. Also, I will add one other thing: his Google Drive may end up being shut down and he won't be able to access the episodes he may have - assuming he has them.
To sum it up, you'll be lucky to get your money refunded if anything.