As one of its daily deals, THAT Daily Deal offers the Doctor Who-Inspired Night Flight T-Shirt for $9.99 with free shipping. That's $15 off and the lowest total price we could find for such a shirt. It's available in sizes from S to XL. Deal ends December 23.
Size XXL is also available for 99 cents more and 3XL for $1.99 more.
Note: It's not guaranteed for delivery by Christmas.