Burn-in comes from using phosphors in the screen, - CRTs and Plasmas will burn in, LCD won't.
+1 to the backlight bleed issue - cheap monitors (regardless of backlighting type) are prone to some nasty bleed from the lighting, so the edges (and sometimes patches in the screen) are brighter/washed out and it can ruin the overall image, especially in a dark environment.
Also, be mindful of the type of panel the monitor uses - with a budget of a grand and a half, there's no need to bother with TN panels.