I volunteer for the local hospice charity shop and a national charity. The local one is allowed to price with great flexibility the National charity has a guide and they must stick to this guide. The manager has herself bemoaned the level of prices and has raised this with the regional manager. She is not allowed any flexibility.
So the local charity has most dresses at £4 to £7, with the £7 one being for example a perfect condition Hobbs dress, That Hobbs dress in the National shop would be priced at £15.
Lots of the very good stuff is sold on EBay, stock is also rotated round shops, then after a time it is ragged and sold per kilo, the price of rag has dropped by 50%. Donations that come in vary, I would say at least 10% cannot be sold at all, broken, filthy, hazardous. They are then put in our huge bins which obviously have to be paid for.
Charity shops are there to raise money for the charity. Some such as The Salvation Army do directly help the poor because that is their philosophy. My local one gives out free school uniform and also if a homeless person presents themselves at my local one they will kit them out with a complete outfit for free. Unsure if that is their national policy. This shop also always has a few books for 10p each.
Paperbacks are sold at £1 in my local, children’s books are 50p and paperbacks £1.75 in the national one. One that I do not work in sells DVD, Books, CDs at 4 for £1, any mix that you like.