Somebody know why IHS Jane's book , is very expensive ?

You don't mention which book you mean but in general their productions:

Are very detailed and have to be updated regularly;
Have a large number of illustrations; and,
Will have limited print runs and relatively small sales.

All these contribute to making books expensive.

The fact that there are no economies of scale because of the relatively low demand is probably the most important factor. Once an edition goes out-of-date (ie every year) it will not really sell so anything that you haven't sold in the year is effectively waste paper. It isn't like a popular novel which sells in high numbers, and whose printing isn't going to go out-of-date - you can continue to sell the books you have until they run out.