I'm confused, why are you skeptical, that model gs air is the closest match to a nautilus in airflow, vapor & taste. All the GS series can use the same replacement heads.
There are several authentic eleaf GS series clearo's,,, GS air, GS air 2, GS air M, GS air MS & GS tank, all range from $8.20 ~ $15
IMO, The GS series are the most underrated inexpensive clearo's available.
You do have to watch out for clone/fakes.
I would like to know where to buy authentic aspire nautilus heads for $8.20 per 5 pack, source please?.
They are $8.95 at evape US