If you don't spend time planning, you'll spend it writing. And if you don't spend time writing, you'll spend it editing. If you don't spend time editing, then packaging becomes enormous and takes longer. If you don't work on packaging and spend time on it, then querying will take longer, because you'll be faced with more rejections. And finally, if you don't spend time querying, and just take what you can get (and that includes self-publishing—no slam on it, but it is something we do without spending any time on querying), then you will spend that time on marketing.