About four years ago, I was teaching 5th grade. I was given an iPad to use with my students. I spent several hours researching ways I could use this amazing new device with my class of 30 kids. It was the new iPad 2 that had just come out in stores. There was an amazing rear camera and this new feature I would learn about called Airplay. I discovered that the new version of the Apple TV had just come out and would mirror the iPad onto a television or other HDMI compatible device. I had a VGA projector in my classroom, and would need a converter to get it to work. My principal purchased this equipment with the understanding that I wasn't sure it was going to work. It did work, so for about $140 in equipment I could project my iPad for my class wirelessly.
AirServer -$14.99 (bulk pricing is available)
Apple TV- $99