Cdjapan has the 25a at 15820 yen shipped to Singapore via registered SAL, 17800 yen via EMS.
http://www.cdjapan.co.jp/goods/goods_detail.html?KEY=NEOGDS-90706
There's a 25a on ebay.sg right now at 220SGD Buy It Now, essentially 17800 yen.
http://www.ebay.com.sg/itm/290999146965?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649