Save Time _ Sure, you could make your own web sites and headers if you have the graphic design skills, the software, and the time. However, you may find your time better spent on developing and marketing your web site. What is your time worth? Even if you have the know_how and the right software, do you really want to spend your time on this time_consuming task? You would have a better chance of making money if you get your site online faster, and put more time and energy into marketing your site. Save Money _ Hiring a designer would save you time but can be expensive _ especially when you are creating multiple web sites. For about the same price you would pay to get one designer_made graphic, you could get a whole collection of quality, pre_made templates.
Templates save you money: If you use a royalty_free template, it likely costs less than hiring someone to create a custom graphics package for you. You could easily spend hundreds (or possibly thousands) of pounds on a custom motion graphics opening, for example, whereas you can frequently purchase a royalty_free template for under £200. Of course, the royalty_free template isn't as unique as a totally custom template, but it definitely costs less, and you could always customize the royalty_free template to make it more unique for you.