Regular edition (without the deluxe booklet) is still available and it should always be since I don't think it's limited in any way. It's like how the CD+DVD editions of Kuu's "secret" and Namie's "PLAY" are still available: it's not a limited thing so it should be pressed/produced regularly.
And... it seems now that the limited edition of "SWEET BLACK" is actually *still available* at YesAsia despite my earlier post. For some odd reason, one entry says it's out-of-print while but when you click on the
actual page, it's still available. Go figure.