I just put circular knitting needles in on my search engine and the first result which came back was for angelyarns.com - their Addi Turbos (lovely needles - metal ones but lovely) go from £3.75 to £5.50 - 2-9mm sizes. Woolyworkshop.co.uk has INOX brand ones - 2.5mm or 2.75mm 40cm length for £2.50. Think if you have a bit of a trawl you will soon find! I would definitely suggest if you can buy the longest ones, cos then at least it’s possible to knit something else on them - get the shortest ones and you maybe stuck with a needle you can only knit daleks with - which I would say is a tad limiting to say the least!!