How it works at all of the Goodwills that I have shopped is that the 50% off color starts on Sunday. On Friday and Saturday the residual sale color items are started to be removed to be resold as bulk clothing to either be resold to other thrift operators or exported, usually to Africa, or Asia. So if you want to get the best deals on the 50% off stuff shop on Sunday or early in the week.
If you are really interested in how Goodwill is operated, check out this link. The US Department of Labor provides Goodwill Industries with waivers that they do not have to comply with minimum wage laws. With all of the Union haters focusing on Walmart, why not a focus on Goodwill Industries?
They don't have to pay minimum wage to the developmentally disabled folks who work in sheltered workshops who would otherwise have nothing to do with their days. Otherwise, no. Let's be clear.