Education is expensive

An interactive world map!
The concepte's great, children learn geography by pointing ammusant the 2 cards (ie: front and back) with a special pen TAG, and learns a multitude of information on the planet that shelters us and peoples cohabit.
But to taste all these funny things we must acquire the TAG says not supplied pen, 50 by itself + 20 of the world map, this makes you all to 70.
Is it expensive? YES
Is it worth 70? ... Yes also.
The only real downside is that the absence of the TAG pen, so essential, is not enough emphasized. Trap? ... You see.