Hey!, yes, I am from Mexico City!
First of all, the legal status in Mexico is kind of bogus this days as the comercialization of vaping gear is still prohibited by Cofepris (México´s FDA), but last year a supreme court ruling stated that comercialization of vaping products should not be prohibited.
This ruling STILL does not permit the comercialization of Vaping Products BUT suddenly the COFEPRIS stopped the witch haunting of Vaping Stores, so at the present moment we are safe.
Vaping has been always permited, just not the comercialization of vaping products.
On the other hand, the vaping industry in mexico (specially in major cities) is flourishing, at least in Mexico City we have decent vaping stores with good prices, decent eliquid brands (crazy cheap about 5 dlls per 30 mls) and reputable online retailers.
I am 100% sure you won't find a B&M in Riviera Maya, you can order from a domestic online store (shipping will get there in 1 day) or bring your own stuff
I will also be at Rivera Maya (Maroma Beach) on August, if you need anything, just let me know!