Lots of fake signs on ebay sell for decent $$$, esp. old wooden signs like this turd:
http://www.ebay.com/itm/251043662125...#ht_500wt_1182
No way is this real. Boxes of this vintage would likely have dovetail joints, and the chances of an "end" from an otherwise broken box surviving with lettering that dark is highly unlikely. Nothing about this item passes the smell test.
It's either some "craft fair" type reproduction from the 1970s/80s, or just a scammer who got some old boards (probably from a broken desk drawer/dresser drawer etc) and a stencil kit. Then brush on some polyurethane to "preserve" the thing and hide your tracks.
Sad there are so many morons out there, although for $30 if all you want is decorative value (which is probably what the buyer is was seeking), no big deal I guess. But it is still shady business.