JessEsq. hit the nail on the head, but to add in my two cents. In addition to the more immediate concerns about Medical Directives, Guardianships, etc., the will is about making the probate process easier for who you leave behind. For example, you will need a will, or the probate process, to be able to sell real property that has the deceased name on it--no will just means that you're making more work for whoever gets the property. Same thing for accounts that are not in your name, 401k docs, etc.
A war story--A widow had to pay nearly 4 grand to buy out the nonexistent interest in real property of her infant son to be able to sell property she and her husband owner prior to marriage (by 1 month) because husband died sans will. Why? Well, real property owned prior to marriage passes to your children, not your spouse. So a toddler owned half the home, but the interest that was "separate" was approximately $500. But because he was a minor, the sale had to be approved by a court.
Another thread is currently going on with a person who was "told 750-1000" for the cost of a will. The lawyer then charged $2500 for the document. The real problem isn't the overbilling (although, wow, that is a problem), but instead not having an agreement in writing up front-the first thing any lawyer should do. A simple will package should absolutely be a flat fee purchase-not hourly.
Lastly, do not do legal zoom. My statement about needing documents to transfer real estate? You know what, that's only for my state. Legal zoom is boilerplate. They give you a form, and you fill it out, then forget to have two witnesses sign it, have it notarized, and whadya know, you've got a piece of paper that says what you want, but doesn't prove what the court needs. Legal Zoom is like going to WebMD instead of a doctor, but whatevs, vaccines cause autism, right?
To paraphrase the old Eli Whitney story, you're not paying for the document to be filled out, you're paying to have the questions asked and procedures followed to have the document filled out correctly.