The bookstore is merely a distributor so the books and manga will all be priced the same as any other bookstore. Although the selection is much larger, and has multiple translations, which is a big advantage over most other shops.
Price range is $18-25
Hobby Lobby Finally has a Complete assortment of DIY manga and Ani
Around $13
It all depends on what you're looking for and how much you would want to spend. Because they have many different things to choose from and all the prices tend to range. All in all, I'd just say it's better to go and see.
Depends on whether you're buying English or Japanese. If you're picking up a manga or book that's been translated by an English publisher, it will cost as much as any other bookstore. Japanese language material, however, has a noticeable import cost markup. A volume of manga or paperback novel that would cost the equivalent of ~$6 in yen is closer to $10. That being said, I love the convenience of being able to browse and buy physical books, so I happily pay that import fee.
Thanks! Your answer is awaiting moderation.