Ebay offers Refurbished Apple iMac M1 24" Retina 4.5K All-in-One Desktop (2021) for $518 with free shipping.

Product Description:
The Apple iMac 24-inch Silver with M1 processor offers powerful performance in a sleek all-in-one design. It features a 24-inch IPS display with a maximum resolution of 4480 x 2520 pixels, integrated graphics, 8GB DDR4 RAM, and a 256GB PCIe NVMe SSD. The iMac comes with macOS 11, Bluetooth 5.0, and 802.11AX wireless compatibility. It is perfect for business use and comes with a wireless keyboard and mouse.

• This Refurbished product is tested and certified to look and work like new. The refurbishing process includes functionality testing, basic cleaning, inspection, and repackaging. The product ships with all relevant accessories, a minimum 90-day warranty, and may arrive in a generic box.
• 24-inch (4480 x 2520) IPS Display
• Apple M1 Processor (Octo-Core, 3.2GHz, 4MB Cache)
• 8GB DDR4 Memory
• 256GB PCIe NVMe Solid State Drive (SSD)
• Integrated Apple M1 7-core Graphics
• No Optical Drive
• 2 x USB 3.0, 4 x USB-C
• Wireless Keyboard and Wireless Mouse
• 2MP Webcam
• 10/100/1000 Gigabit Ethernet, IEEE 802.11Wi-Max and Bluetooth 5.0
• Operating System: macOS 11
• 18.1" x 21.5" x 5.8" (HxWxD); 9.9lbs
• Energy Star Compliant, Gold EPEAT