On Quora a while ago, I answered the question which forms the title for this blog post. Below is an unedited version of the answer which I gave.
Their is no “economical way” per say. But assuming you are following lean startup principles, you want to make sure that its a Minimum Viable Product (MVP) which is build with the barest minimum features which are needed. For a startup you are trying to validate and learn more about those you want to market the product towards.