my money is on about 18 to 20mm - 22mm would reach all the way to the edge - and considering the price at way below $10.00 i just don't see it

that would create quite some competition for their own melo
Well, not quite. Melo is a sub-ohm tank so it's not going to be a competition to the Air tanks. There are millions of us, tight-draw-low-wattage-tootle-puffers, in this world, who are not interested in sub-ohming.
I think Eleaf is very smart--they are not only covering all their bases but they are offering very attractive prices. In case some stray tootle puffers want to try a sub-ohm tank, they can do it for very little money. Win-win. If they would only offer a tank with an RBA deck, I'd be their customer for life.
Speaking of which, I wrote to Kanger and suggested that we need a tank with OCC coils and an RBA option for people who prefer to vape in the 10-20 watts range, and they actually responded; their engineers are going to consider my "valuable suggestions." Just saying.
