i checked the eyelighter out. It is indeed quite clever; however, i do think the price is too much for what it is. Maybe you can look for a welder friend to build a frame for you and stretch the canvas over it yourself, then paint it with matt or satin white paint over. All that custom work still propably should cost you less than 250 bucks.
Or just simply buy a $10 white foam board at an art store, then fold up the 2 sides. To hold it up you can buy a cheap display stand or aluminum easle that can hold and turn the display board to horizontal position (can also be found at a good art store). The board and easle should cost you around $40-$80, depend on the kind of easle you want to pay for. There you go: quick, cheap and easy solution.