As one of its daily deals, 1Sale offers the refurbished Apple iMac Core Duo 2.4GHz 20" Desktop, model no. MB323LL/A, for $449.99 with free shipping. That's $114 under our March mention of a refurb (which had half the RAM) and it's the best price we've ever seen. (It's a current price low for a refurb by $629.) Features include an Intel Core 2 Duo E6600 2.4GHz dual-core processor, 20" 1680x1050 LED-backlit LCD, 1GB RAM, 250GB 7200 rpm hard drive, ATI Radeon HD 2400 XT 128MB graphics, SuperDrive, 802.11n wireless, Bluetooth 2.1 + EDR, webcam, and Mac OS X 10.9 (Mavericks). Deal ends today.
A 90-day warranty applies, although it's unclear who supports it. Expect delivery to take up to two weeks.