It's called supply and demand, and it's the way things have been priced since the dawn of commerce. The only time the price is based on cost is when the market is competitive enough to drive that price down, and the cost acts as the floor. Even then, if you can get your costs below those of your competitors then it's your competitors cost that can act as the floor.
The way things should be priced is based on the value it gives you. If your service makes me or saves me $100 of value per month, I should be prepared to pay up to a little below $100 for it.