There are advantages and disadvantages of both fixed rate and hourly rate. I need to evaluate my preferences as well as the client’s requirements while choosing a billing method. Most freelancers use a mix of hourly and fixed pay rates pricing for different projects.
While I tend to base quotes on an hourly rate, my experience makes things faster. Yet one shouldn’t be penalized by an “hourly rate” for being experienced. A client hires me for my years of knowledge and acquired skill, not machinelike piecework in a vacuum. I’ll charge more if the job includes strategy, consulting, or managing other people.
Plus, hourly is not always equal to quality work. And a special creative task may translate better to a per-project rate. My productivity fluctuates. Sometimes I’m very inspired and I get things done super quickly, and sometimes it takes me more time to complete a project. This has nothing to do with the client, so they shouldn’t pay me more or less based on that.
Over the years, I’ve maintained a relatively consistent rate while developing new or redesigned websites and I charge clients per hour. The hourly approach makes more sense for me since there are so many unexpected turns in a design project. I’ve worked with clients who keep adding changes that affect the entire design. This can result in hours of extra work that wouldn’t have been anticipated if I charged them per project. Charging per hour protects me from having to eat the cost of all those extra hours.
Now, as a veteran freelancer I have a habit of increasing or changing my prices every couple of years because I’ve consistently improved my knowledge and skills… plus… well, inflation.
In reality, my “hourly” rate is often a composite of time and task charges, a rate which takes into account the overall value of the website project AND represents my value as a professional designer/developer to businesses, individuals, and organizations that choose to contract with me.