Plextor PX-708UF/JP was found in Akihabara stores accordig to Impress Akiba Hotline. PC-Success sells them for 31,800 Japanese Yen (about 260 USD) for unit. The PX-708UF is based on Plextor PX-708A 8x DVD+R writer which can write to DVD+R, DVD+RW, DVD-R, DVD-RW, CD-R, and CD-RW media.
Also, Plextor PX-708A Black Bezel drive was found for 27,800 Yen (about 230 USD).
Pictures from Impress site