Amazon.com has set 2505, Garmadon’s Dark Fortress from the Ninjago series, for $51 today. That is not a sudden change in Amazon’s price, because the set has been between $50 and $55 for the last few weeks. It is $69.99 from LEGO or any other source I have found, so Amazon is definitely the place to purchase it.
I own this set, and would not pay the full retail price of $69.99 for it. Between $50 and $55 is good.