The cost of tickets multiplied by the number of tickets available seems to add up to more than the value of the prize. Why is this?

We want to give our customers the chance to win luxury prizes for a fraction of their price and have fun while doing so, however we incur costs for doing this, and we are also a business so naturally want to make a profit. The surplus money covers overheads such as office rental, staff costs, website maintenance, internet/phone connections, payment processing fees, marketing costs, taxes and our business profit.