Amazon.com has 4TB Toshiba 3.5'' SATA Internal Hard Drive (PH3400U-1I72) for $112. Shipping is free.
BestBuy and BestBuy via eBay also has 4TB Toshiba 3.5'' SATA Internal Hard Drive (PH3400U-1I72) for $112.99. Shipping is free, otherwise select in-store pickup if stock permits.