This Creative Playthings wooden puzzle box just went up on eBay; it's $6 (+$8 shipping) right now, but it's the kind of thing that can go quite a bit higher, I'm afraid.
On the other hand, the auction ends July 4th at 18:31 PDT, right in the middle of fireworks on the East Coast, so maybe no one'll show up at the end.
Meanwhile, this sweet set of Bauhaus blocks by Alma Siedhoff-Buscher was reissued by Kurt Naef in the 1960's and comes with the original box. Which means it starts out higher: the opening bid's $300. Unless you're ready for the kid to gnaw away at your collectibles investment, you'll want to keep shopping around. Ends July 1.
Vintage Creative Playthings Wooden Puzzle Box Toy [ebay]
Bauhaus Construction Set Kurt Naef circa 1960s Perfect [ebay]
I like that Creative Playthings toy, but Melissa and Doug makes a nice dovetail-jointed box with 12 holes and a great variety of shapes (octagon! trapezoid!).