Originally Posted by erictby:
There was 4 or 5 bus stop for A21/N21 (A21 day & night time, N21 midnight) at TST (from New World to TST Police Station) along Nathan Road.
I think the 2 possible bus stop for the OP was, the one before Haiphong Rd (the bus stop was at the opposite of Mirador Building) and the one in front of TST police station since his last location was the China Ferry terminal.
But I never catch the A21 or N21 buses, just check the exact location yourself before you leave as I mentioned early.
If I was you, without a lot of luggages and before midnight, I will take MTR from TST station or Jordan station to Tung Chung Station (Remember change your train at Lai King station), it cost HKD17 (HKD15.10 for Octopus).
At Tung Chung station just come out from Exit B, walk straight to another entrance at other building (Just follow other people. A lot people, espeacially local people, will go to the bus station). There was Tung Chung Bus Station/Terminal (I no sure it was a Station or a Terminal). Take S1 or S64 to Airport, it cost HKD3.50.
Total cost HKD 20.50 (HKD18.6 for Octopus) compare with A21 HKD33 (N21 HKD23; But remember, it for midnight only. N21 was you only solution, if you leave at midnight since taxi was not your selection). I think this method was the cheapest method but time consuming because have to waste a lot of time for the few time vehicles changing.
Hope this help you.