When I stumbled across this series last fall, I was completely consumed by it - and it's rare I will sit and watch TV! Can't wait till it starts back up again! 
One of Target's Daily Deals today is Season 1 of Downton Abbey for only $13.99 shipped! It's selling for the same price on Amazon but you will need to make a $25 purchase to qualify for free shipping if you do not have a Prime Membership.