A light box is a box with a light in it. Pretty simple stuff. I just can't bring myself to pay $50 (on the low end) for one. This one was put together in about 15 minutes and cost less than $15. Lights of America makes a 13" florescent lamp
that I bought at Wal*mart for about $8. The box is a Sterilite storage box with a frosted bottom and cost about $4. I like making stuff, but I like drawing more so this is as simple as it gets.