As the title of this thread is IR on the cheap, here is a link to a web page that has a Photoshop Action for FAUX INFRARED - ie false infrared - and you cannot get cheaper than that - use your own pics and treat them in post processing, no gadgets - just your imagination. This site has a lot of Actions for Photoshop and they are worth learning how to use as they save you from re-inventing the wheel each time. This is an excellent site and has actions for many different versions of Photoshop -
http://www.thelightsrightstudio.com/TLRFauxInfrared.htm
Have fun and enjoy playing - the only limit is your imagination.