Considering that the product shipped in the US just this past week, I'm not sure how available it will be in HK, let alone at the airport. Currently, it's showing a 3-4 week shipment period for online orders in HK.

The cost of the base model is HK$16888, or US$2176 (the base price is $2199 in the US). It should be tax-free ... I bought a few things at the Apple Store ifc last month and paid just the sticker price (no tax).

Came out much cheaper than buying back home in Taxifornia.