So I was curious about that range at SuperCheap, they stock a range of paint called 'ColorSpec', which is a mix-to-match paint system, provided by CONCEPT paints.
The confusing part is that their range specifically says to use ACRYLIC topcoat ONLY.
After some research, I managed to get a look at the paint codes on the bottles and gave Concept a call.
All the tinters started with E (E-18, E-26, etc)
Basically, there was no 'E' series on Concepts website, despite them making the paint. The hell?
I decided to actually make a phone call!
Turns out the 'E' stands for economy; same match accuracy, just less pigment in the economy range (so more coats needed).
Super Cheap Auto = Economy range
Autobarn = Normal Range
Auto1 = Normal Range.
After a quick chat, the economy range is sometimes good for 'fading' a blend, because, less pigment, means an easier fade; otherwise, the 'normal' range is better.
I also confirmed that all the 'NoMix' paint range (which is Concepts) is 2k compatible, even this 'Acrylic Only' ColorSpec stuff.
Same system, all the same paint, just different name.
Hopefully that's useful to someone!