A: So, tell me about the movie. B: Oh, it’s one of those cowboy stories. The usual thing. A cowboy rides into town on his horse, cleans up the town, and rides out with the girl. A: Sounds like quite a story. B: Yeah, really.
Usually it would mean that the story was very (quite) interesting or unusual, BUT, in the context, I think the speaker was being sarcastic and meant exactly the opposite. In other words, it was a veryunoriginal or ordinary story.