have a nice day and fyi mine was not a post but a comment and what I quoted was from an AOT official at the airport so there and now may I please invite you to go get a life and bugger off?!
You can use it even if flying economy it is available for also people over 60 according to an AOT official as he was letting a woman behind me in through the fast track channel or with a disability not just biz or first class
if you go to Tokyo try Komehyo which is one of the largest ones in several locations from Ginza to Shinjuku to Shibuya etc but then there are smaller ones all throughout and I'm talking brands like Tag Heuer to Rolex to Cartier to Seiko to Omega all sorts for all budgets plus as a foreigner you can claim the 7% vat or sales tax refund on the spot or at the airport, in Thailand you can go to Chatoochak market on the weekend I have seen a few stalls selling watches in the antiques section but many more in the big red building across the road where they run the flea markets, good luck!