Another option for an inexpensive screen, if you don't mind some DIY work, is to buy a roll of Wilsonart, Designer White, laminate from a kitchen or cabinetry supplier. Fashion Grey is an alternative color if you do not have a very dark room.
When I was researching screens, I found several articles where the screen help up in color testing to $1000 plus manufactured screens. Here is one article with some useful information on the pros and cons of both.
Some users reported a rolling effect in the screen after time. Personally, I think this may have been in how they mounted it. I built a frame that used a lot of pocket hole jointed, cross bracing. This made for a very rigid frame with a lot of perfectly flat surface area for the adhesive. Use a strong, but non-clumping, spray adhesive to retain flatness. 2 years plus and the screen is holding true. Cost was about $200 for the laminate and another 150 in wood and hardware for the frame. It was also a great excuse to buy a pocket hole jig, that I use regularly now for other projects.
