Harumph! Well I found out why the Bamboo needles were so cheap - not a single set is of a consistent size! The worst ones are the ones marked 2.25mm, which are in fact nearer to 2.75mm. Ironically this worked in my favour - I needed some 2.75mm for the socks I'm right in the middle of knitting.
Having discovered this, I set about measuring all the others, and found the most crazy results. Most sets have one or two needles that are close to the right gauge, the rest are mostly larger than what they are marked as. Some are the right size at one end, and a different size at the other! When you put the sets together and scrutinize them closely, the difference is just about noticeable. Obviously made in a factory where the tolerance is set as a few millimetres, or perhaps they just guess!
I contacted the seller to alert them to this fact - and to be fair, they were very apologetic and have offered to send me something by way of compensation. I didn't ask for a refund - I need the needles right now and am happy to work around their idiosyncrasies. My reckoning being that if you're using five needles, the size difference will even itself out over the rounds, and it probably won't make any difference at all on the large sizes.
If you're buying, just be warned - check with a needle gauge before you start!
6 hours ago