I agree that learning to build your own coils for an RTA/RDA is the best way to ensure an ability to vape without relying on vendors who may or may not survive the vape apocalypse. The right collection of RBA/RTA
tanks will live on through time. Replacement glass parts will come in handy.
A few spools of wire are a must. Rayon and Cotton will always be available. Learning to make your own
juice if you want to vape something other than tobacco flavors is also a must, IMO.