oh wow! Thanks for letting me know. I was planning to get it at iconsiam but now that you mentioned the new store at the airport, might as well purchase there! Thanks a lot!As far as I know the prices on the website include tax and yes as a foreigner you can ask for tax refund. The form is filled out and given to you at the boutiques. You need to get one stamp at the airport and then show the item again after security, to get the refund, either on your card or in cash. Suvarnabhumi Airport has a beautiful new Cartier boutique which carries watches and jewellery and it's automatically tax free for tourists on international flights.
ps just realized that prices in europe after tax refund is the same if you purchase it in Thailand. might even be cheaper there after refund!