I just also recently updated the Wikipedia entries for Ayu and her discography to reflect her 49th and 50th official singles (51st and 52nd if including failed "Nothing from Nothing" and digital "Together When..." singles).
Article on Ayumi Hamasaki (section: 2007-present: Market beyond Japan; see bottom of section)
Ayu's discography, singles section
BTW, I just created an account on CDJapan! Don't know when I will be using it, but if I have my own money, I might want to take advantage of "coupons" and save on Ayu singles as well as anything you need for Japanese pop and media!