In my experience (10+ years freelancing), you make the real money when you re-engage with a client. I tend to think of the first contract as just a way to open

In my experience (10+ years freelancing), you make the real money when you re-engage with a client. I tend to think of the first contract as just a way to open the door. So in that respect, it really doesn't matter which way you charge... just make sure you do an awesome job and help that client earn a living from their website, so they can re-engage with you later for much larger projects.