I can only buy those that are Sold and fulfilled by amazon. As others are not available for free shipping to singapore.
R9 270X:http://www.amazon.com/s/ref=sr_nr_p_6_2?rh=n%3A172282%2Cn%3A541966%2Ck%3Ar9+270x%2Cp_6%3AATVPDKIKX0DER&keywords=r9+270x&ie=UTF8&qid=1385905952&rnid=303116011
7870:http://www.amazon.com/s/ref=sr_nr_p_6_3?rh=n%3A172282%2Cn%3A541966%2Ck%3A7870%2Cp_6%3AATVPDKIKX0DER&keywords=7870&ie=UTF8&qid=1385906117&rnid=303116011
GTX660:http://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Dcomputers&field-keywords=gtx660&rh=n%3A541966%2Ck%3Agtx660
R9 270X:http://www.amazon.com/s/ref=sr_nr_p_6_2?rh=n%3A172282%2Cn%3A541966%2Ck%3Ar9+270x%2Cp_6%3AATVPDKIKX0DER&keywords=r9+270x&ie=UTF8&qid=1385905952&rnid=303116011
7870:http://www.amazon.com/s/ref=sr_nr_p_6_3?rh=n%3A172282%2Cn%3A541966%2Ck%3A7870%2Cp_6%3AATVPDKIKX0DER&keywords=7870&ie=UTF8&qid=1385906117&rnid=303116011
GTX660:http://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Dcomputers&field-keywords=gtx660&rh=n%3A541966%2Ck%3Agtx660