My son too reads them several times. I can't figure out why he would like to do that, but he says it is like watching your favorite movie over and over again. SO, if he wants to read it over and over, I'll pay the price!!!!!
15 minutes? Your kid is quite the speed reader! But yeah, I get it, you're exaggerating. Let's not forget, thought, that a lot of hardcover picture books are $15-$18, and there's way less reading time built into those. The way I look at it? This costs less than going to a movie and will probably last about as long. You could always get it at your local library, but you'll probably have to wait a while.
My three teenage boys buy these themselves with whatever gift money they recieve, or from their paychecks. They've got them on their own special shelf in their room. They've been collecting them for *years*. And I cannot tell you how many times each book has been read, over and over and over again. The only one anxiously awating this newest release is 13, the other two now too "mature". But I know for a fact that once the younger one buys and reads it, the other two will borrow it. This series, and the Rick Riordan books.
I'm very selective about the books I buy for my kids. We're huge library-users, but Wimpy Kid books are ones both my kids (ages 11 and 15) will read again and again. So they're must-haves, in my opinion.
I also don't like buying books my son will only read once, especially at full price, so many of our books are bought used or checked out from the library. However, this series is one of his favorites. We've bought the entire series, he's read all of them at least 3 times or more, and it continues to be a favorite.