Having worked as a chariity shop manager,I would like to point out the overheads a charity has-premises, shop staff(usually 2 paid at basic wage),regional and admin staff,energy costs,etc..Volunteers are greatly appreciated.They also have the problem of people leaving bags outside overnight,usually unusable items.This is fly-tipping and causes a lot of unnecessary work.Sorting through donations can be a time consuming and sometimes unsavoury job-clothes only fit for rags,smelly,unwashed clothes and general household rubbish.One manager I know even found a dead dog in one bag.Many customers expected to be able to bargain with staff to knock the price down.Furniture has to be collected-more costs,petrol,van,etc.
We priced our clothes accordingly-cheaper for unbranded and a scale for the high end brands.Each shop had a chart to show them which brands were most expensive.Only good clothes were sold-we had to check for holes,missing buttons,etc.The same went for books,toys and bric-a-brac-all checked for quality safety,etc.
I loved the job but I would just ask people to remember that it has its unpleasant side and charity shop staff work hard for minimum wages-my choice because I believed in the charity.
All that said,charity shops still serve a useful purpose and are a large source of income for a charity.I agree that some of them are a little over-priced but the majority still offer bargains and could not function on the miniscule prices that some people seem to think is their "right."