Recommend Me a Portable Video Projector

My wife is looking for a video projector for her business, and I know nothing of such things. I'm not even sure what information is really relevant.

The laptop she'll be using is Win7 and has a 15-pin VGA port and an HDMI port. It will primarily be used around her shop for classes or demos of quilt design software, and the classroom is a 13'x17' space, in case that figures into the lumens or resolution. She'd also like to use it for Powerpoint/slideshow presentations at meetings around town so it needs to be portable.

The most she's willing to spend is $300, and less is always better. Looking at NewEgg and B&H Photo there are several under that price, but I can't tell what's good and what's junk. Are there any brands to avoid, or other information to take into account?