This deal has ended.
Overstock.com drops the 14k Gold 1/2ct TDW Round Diamond Engagement Ring (HI, I1) from $666.99 to $599.99. Better yet, activate the $35 off $500 coupon in this link to cut it to $564.99. With free shipping with a new account, that's $10 less than the lowest price we've ever seen. The color of this diamond is very good (G-H). It features a round prong set diamond and a pave diamond band. There's no sales tax (except UT).