Yesterday I bought my son (he's 2, soon to be 3 tomorrow) a $1 puzzle of United States. I bought it because we have a much bigger floor puzzle of the US but it's too big for him to keep trying to put together, it gets in the way. He instantly fell in love with the puzzle. Last night I watched my little boy put together that puzzle. He knew where each piece fit. I was amazed. He fell asleep laying on top of the puzzle. When he woke up the first thing he did was pick up his puzzle and gaze at it lovingly. The only way I could get him to eat his breakfast was to put the puzzle on the table besides him. After he ate his breakfast he was highly upset because a piece of the puzzle was missing (it ws Kentucky). I found the piece and he was instantly happy again, clapping his hands with joy.
I think it was a dollar well spent.