If you’re a “Harry Potter” fan looking for the ultimate collector’s item, this has to be in the conversation: It’s the house Harry grew up in . . . and it can be yours for a mere $620,000. This would be the house at “Number 4 Privet Drive” in the fictional town of Little Whinging. Before he knew he was a wizard, Harry lived there with the rotten Dursleys: his Uncle Vernon, Aunt Petunia, and cousin Dudley. The house has 3-bedrooms, and it’s a lot more modern inside than they made it look in the movies.