I have been to a few top shelf places in BKK and the best I ever saw was Don Julio. Not the 1942 DJ ($125 a bottle in states), just Don Julio ( bout $45 in states). Now some people believe Patron is top shelf. To me that's very run of the mill tequila. Good for mixing but sippin....I'll pass.
I have not see Gran Marnier at Topps, Villa has GM and Contreau but as you said...for a price. Patron is the same at Villa. Waaaay over priced for what one gets in return. Best to stick with Maker 46 Bourbon....:)