Projectors and screens rarely have much in the way of spectacular savings and sales rarely kick in full gear.
If the room you are in is not just one with no windows, but actually has dark paint on the walls and ceiling with dark carpet, which can greatly benefit from a top tier screen, then considering a DaLite screen with the HD Progressive material may be a long term investment worth your time.
www.legrandav.com
There is a cost associated with them, that is beyond some people's budget, and the jump in quality I'm not sure is worth it for most people.
In reality, in a proper room, most people are extremely happy with what Silver Ticket screens deliver.
Available in 120" and 135" diagonals (and other sizes), for the money, it is hard to beat.
If you need to go acoustically transparent, Silver Ticket is decent, but I would turn towards SeymourAV.