Return rail tickets plus 2 nights' stay in a Travelodge for 2 adults, cheaper than the tickets by themselves!
This is for the various Edinburgh Travelodges - Haymarket, Central, Cameron Toll, Shandwick Place (and West End). The deal site says you need to book on the phone but you can get these prices (and better!) on Superbreak's website with the 2-night rail break offer (link in first comment).
Also, the tickets you get have the advantage over Advance tickets that you can return any time (although it is recommended that you reserve a seat before departure), rather than on a particular train.