Babies and kids outgrow their clothes long before they wear them out; therefore, people would rather buy second-hand and save the cost of buying new.
With adult clothes, it depends on what you're selling, and you have to choose carefully what you offer. Men's Levi's, for instance, sell in a heartbeat. My professional work clothes, all brand names at a time when brand names mattered, never lasted until noon on sale day. One of my favorite sales was a 20-year-old Evan Picone suit. That's right, 20 years old. It was classic and tailored and still favored in the working world. IIRC it cost $200 at an outlet mall and still fetched $50 at a yard sale.
A London Fog or Burberry rain coat wouldn't last long, nor would a pea coat of any brand.
If you're offering dresses that are no longer fashionable/in style, have specific fashion "tells" like shoulder pads, gathered fabric at the shoulder, or prints/plaids that are no longer trendy, they aren't going to sell at any price.
Run-of-the-mill, off-the-rack women's dresses, pantsuits? Cut the buttons off, take zippers out, rip them into fabric strips and make rag rugs out of them. People will buy rag rugs