Invitation cards are not necessarily expensive, but it is possible to make them as expensive as you want them to be. It all depends on the type of paper, the design and the add ons to the invitation. For starters, it is possible to buy invitation cards in bulk quantities for really low prices. Then all you have to do is to print your message on it. But as you go for higher quality paper and personalisation, the costs add up. Some people also like to add small gifts along with the package. In that case, you will also have to calculate the cost of the gift as well.