PSA from me: The only way to get unlocked iPhones is to pay full retail price only at official Apple Online/Retail Store. All unlocked iPhones can be used anywhere in the world, regardless of number of supported bands. 

Also, to people who are buying from China or Hong Kong: Be warned that the model number for sale in Malaysia (A1897/A1905) is different from the iPhones sold there. Same goes for Japan or US iPhones too (unless you go with the AT&T or T-Mobile version).

However, be advised that Malaysian AASPs may not accept warranty claims for models sold overseas. Only iPhones with model numbers sold domestically are guaranteed support by local AASPs.

For more info, checkout this spreadsheet.

^ A1864/A1863 (CDMA) [Sold in US]:  May not be warranted locally. Qualcomm modem, can be used on CDMA carriers in US like Verizon or Sprint. Can't support FeliCa.

` A1864/A1863 (GSM) [Sold in HK/ZH]:  May not be warranted locally. Intel modem, can't be used on CDMA carriers at all. Can't support FeliCa.

* A1897/A1905 [Sold in AU/MY/SG/worldwide]: Fully warranted by local AASPs. Intel modem, can't be used on CDMA carriers at all. Can't support FeliCa. iPhones sold in some Middle Eastern countries does not support FaceTime.

º A1898/A1906 [Sold only in JP]: May not be warranted locally. Qualcomm modem, can be used with CDMA carriers in Japan like Softbank or au. Can support FeliCa so you can use e-money cards like Suica with Apple Pay. iPhones sold in Japan cannot have the camera shutter sound disabled, even in silent mode.