Seems to be a bit of an Ebay "price war" on the cost of these things at the moment with a set of 19 collets now available for as low as £33.98 ER32 Collets UK Supply just had a set delivered (in less than three days) and so far the one's I have checked the runout is less than 0.001.
Did have one bad one though, the 16mm (16-15) collet looks like it had been mis-machined the photos show the unground jaw segments,
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looks like it might have been initially machined a little oversize not leaving enough metal to finish grind to the correct final size.
Given that the collets work out to less than £1.80 each I wasn't too concerned about one bad one but contacted their customer support anyway.
Sadly they couldn't replace the individual collet as they only ship these items as packs of 19 however the seller quickly resolved with a £5 refund for the individual collet.
I must add that it seems that despite being shipped from a UK address that their customer support is most definitely "offshore".
Paul