I love to shop at the thrift stores that benefit charities, do you?
They are ok. The best things to get at thrift stores is clothing.  But it is still a business that feeds a capitalistic venture. 
Oh in my area its a retail establishment run by a charitable organization to raise money
Yes they raise money and meet a minilnal requirement to legally be considered charity but they still have a CEO who owns a mansion. . 
Oh ok are the people that work there volunteers?
I don't know.  Maybe some are but they also have dedicated employees and operating costs to remain in business. 
Is it easy for them to make a profit since most items are donated to them?
Yes, since the items are given for free they can then sell them at competitive prices. 
Ok I noticed the big name ones in my area don't price competetively? They charge top dollar!
the United States also covers consignment shops), and opportunity (or op) shops (in Australia and New Zealand).
History.
One of the earliest charity shops was set up by the Wolverhampton Society for the Blind (now called the Beacon Centre for the Blind) in 1899 to sell goods made by blind people to raise money for the Society. During World War I, various fund-raising activities occurred, such as a bazaar in Shepherd Market, London, which made £50,000 for the Red Cross
Charity shop
A charity shop, thrift shop or opportunity shop (colloquially referred to as an op shop) is a retail establishment run by a charitable organization to raise money. Charity shops are a type of social enterprise. They sell mainly used goods such as clothing, books, music albums, DVDs, and furniture donated by members of the public, and are often staffed by volunteers. Because the items for sale were obtained for free, and business costs are low, the items can be sold at competitive prices.