You will always pay a selling fee of about 13% + 30p per item.
It is free to list items on a personal account, but you will still pay seller's fees to Ebay.
Your fees on the shoes should have been about £3.35p - is that about right?
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)