The Apple Store offers a selection of factory-refurbished Apple iMac desktops, with prices starting from $929. Plus, they all qualify for free shipping. These desktops come with a 1-year Apple warranty, the same as new iMacs. A couple of best bets, with prices compared to new models:

• Refurb Apple iMac 21.5" Haswell i5 Dual 1.4GHz Desktop for $929 (pictured, low by $100)
• refurb Apple iMac 27" Haswell i5 Quad 3.2GHz Desktop for $1,529 ($160 off)