I've found that charity shops have become a bit more discerning in recent years... you used to be able to make an absolute FORTUNE on designer or branded kids' clothes. I think our record was a baby boy's hoodie that we found for £2 and sold on a FaceBook group for £35
. It was immaculate and they're £50 new...
That was a bit of an exception, but there used to be LOADS of things that you could buy for as little as 99p and sell for £7 - £10. We made something like £2500 over a 4 or 5 month period when we were at our "poorest". Took quite a bit of trawling around but we were so broke that it was very much needed
.
But like I said, most places seem to be pretty good at sniffing out the quality items these days and either selling them online themselves, or pricing them higher in the shops.