YesAsia is indeed the most trusted place to get. There are so many bootlegs on the net. Gotta beware.

Actually, they're not cheap especially for the currency used for certain countries. I'm from Malaysia and when I convert the price on YesAsia to MYR, it's friggin' costly. However, you can get purchase those versions which are not Japan versions. E.g Taiwan or Hong Kong versions. Those are cheaper but of course they don't have the bonus tracks and extra stuff.