Well, it may not make much sense for someone in the US to buy it for $30, but it allows someone from overseas to open an account in the US store without a US credit card, and buy stuff there (such as content which may not be available on other stores). They can then also get all the free singles etc too.
So yeah, $5 extra is worth it in that case IMO... A similar way is how I got my US account originally.
People who use Cash Back or discount codes for eBay.