SuperBiiz has it for $625 - $20 off with coupon code KINGCAKE
[Exp 2/20] = $605
with free shipping.
Today only. Newegg
has the Crucial M4 CT512M4SSD2 2.5" 512GB SATA III MLC Internal Solid State Drive for $655 - $25 off with coupon code EMCYTZT1185
[Exp 2/15] = $630
with free shipping. Features up to 500 MB/s read speeds, up to 260 MB/s write speeds, 1200000 hours MTBF, integrated 8-channel single chip controller, and 0.1 ms average access time.