Ok here is my answer

Do not buy children cheap shoes.  Ideally get their feet properly measured etc and buy them decent leather shoes for school.  Even if it means buying from a Charity shop or 2nd hand off Ebay once you know their correct size and width.

If on a very limited budget save money by buying 2nd hand clothes etc but personally i would only ever buy brand new shoes for a child.

Average cost of my sons shoes were £25 to £30 and he is now an adult.