Adorama offers the Seagate 4TB Central Network Attached Storage External Hard Drive, model no. STCG4000100, for $129. This $40 mail-in rebate cuts it to $89. With free shipping, that's $40 under our mention from last spring and the lowest total price we've seen. (It's also a current low by $40.) This PC/Mac-compatible NAS connects to your wired or wireless router for backup or file sharing. Rebate expires July 15.