Hi Ariana.

LuxRender is free, go to luxrender.net and you will be able to download it. No cost. Reality is sold here at 20% of which brings the price to $31.95. 

The Reality gallery has been running for more than two years and you can find  alot of information there.

See http://reality-plug-in.deviantart.com

Hope this helps.

Paolo

https://www.preta3d.com
FB: https://www.facebook.com/RealityPlugIn
Tw: @preta3d
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The Reality Gallery: https://reality-plug-in.deviantart.com