Want to save money on your Christmas tree? Wait as long as you can to buy it. A study found that you can save about 22 percent on the price of a tree if you wait until the week before Christmas to buy it. The research revealed that Christmas Eve is the cheapest time to buy a tree -- with an average price of $47. The most expensive time to buy a tree is Cyber Monday (November 26th), when the average price is $81. The day after Thanksgiving, aka Black Friday, is also pricey, with trees running about $77. (NY Post)