Try https://live.xbox.com/en-US/Flows/ManageSubscription/ChooseSubscription.aspx
Is $35 as cheap as these get? My subscription doesn't expire until January so I'm not sure if I should hold out for a better deal (or for Microsoft to make Gold free).
I bought this but then decided to cancel my order based on people posting that it can be had for even lower. My subscription isn't up until next December so I figure I'll wait for a better deal.