IKEA's Lack table costs just $12.99 and you can transform it into a photo/tracing light table with not too much effort.
After slicing off a large square off the top of the table, you'll find the interior is actually hollow and filled with a honeycomb of cardboard reinforcement. Remove the cardboard, paint the interior a glossy white, attach LED strip lighting, and then top with acrylic sheets.
OK, it's a little more involved than that, but Instructables user Mr. Chutney provides the full details and materials list so you can build your own light box right into your side table.
DIY Lightbox build with IKEA Lack table [Instructables]