Less than RM10 for a huge pack. Sure that's considerably more expensive th|an your average Guardian bleached cotton, but this is unbleached stuff. At least it's cheaper than the other options (Chaddo and Body Shop = RM25 for even less cotton).
Not sure about sterilised cotton. I'll check up on that later, but I assumed it's bleached anyway before sterilisation so there's still still a chance of it having more chemicals vs unbleached (assuming it's not chemically ssterilised in the first place).

Normal bleached capayam cotton (not even Guardian, but the best I have before this - more on that later) vs Muji Unbleached. Note the seeds and different colour of the Muji. The Muji is also considerably thicker plus the fibres are also of longer strands and are slightly looser.
More importantly, how does it vape? More or less, my findings are like the ones from
C-Fu a few pages back.
With the Muji, the initial cotton taste is STILL there on my Taipun - but it is MUCH less "chemical-ly". Not sure if that's just a placebo effect, but for me there's definitely less of the "cottoncrap" feeling - especially compared to the Guardian cotton, which I suspect has perfume or preservatives or whatnot in it because it's the most chemical tasting of the lot.
Secondly, not sure if I'm imagining things, but it feels like it's far more efficient at wicking. Somehow. Maybe it's the looser, longer fibre strands.
Anyway, I need to test more but so far I like what I'm getting. Haven't tried the Bastem yet, maybe later.
the chaddo cotton is about one piece of that Muji cotton. The watson's cotton that I got is advertised as lint-free, which I believe is better for vaping. and a lot of the cottons in thailand are marketed as zero/no perfume/fragrance.