Amazon has 4TB Seagate NAS 3.5" Internal Hard Drive (ST4000VN000) on sale for $119.99. Shipping is free.
Says "Temporarily Out of Stock", but you may still place your order and you will not be charged until the item ships.
No longer available:
Newegg has 4TB Seagate NAS 3.5" Internal Hard Drive (ST4000VN000) on sale for $119.99 - $10 off with promo code VCOBF15 = $109.99 when you checkout via VISA Checkout. Shipping is free. Thanks whirly & Garbanzo
Note, must complete order via VISA Checkout for discount to apply
Note, eligible American Express card holders may qualify for an additional $15 off this purchase [details]
Editor's Notes & Price Research
Our research indicates that the 4TB Seagate NAS 3.5" Internal Hard Drive is $35 lower (24% savings) than the next best available price from a reputable merchant with prices starting from $145 ~RevOne
American Express $15 statement credit when you spend $60+ at Amazon.com