I assume you're looking at the US store from outside the US. If so, it's showing what the price would be for you (and if your local currency is dollars, even if the Australian or Canadian version thereof, it may show in your local dollars and you just don't realize it).
Basically it's not worth worrying about, though if you like you can post a link and ask someone in the US to see what price is showing. People do this frequently--and invariably the US price shows in the US as what's on your Bookshelf.
PS I looked at the Artsy Craft book. It's listed at $3.99.