Newegg has the Western Digital Red WD30EFRX 3TB SATA3 64MB Cache 3.5" Internal HDD for $170 - $20 off with coupon code EMCXVXM23
[Exp 2/14] = $150
with free shipping. Goes for $162+ elsewhere. Features a 6.0Gb/s SATA interface, 3.5" form factor, and is designed and tested for 1-5 bay NAS systems.