How much does SEO cost?

It can cost you as little as nothing except time if you do it yourself.  However, if you choose to have your search engine optimization done professionally, it can cost anywhere from $2500.00 to $5000.00 initially, and then monthly "update" fees from $300.00 to $1000.00! The worst part is that there are no guarantees, and it's likely you'll get caught in some contractual trap which usually means if you don't keep paying their fees you lose all your search engine rankings and all the traffic you were getting!