I've found for smaller sized businesses, or maybe even the mom and pop type folks that want to get their small little project up on the web, a fixed "package" price works great. I lay out for them that they'll have up to X amount of pages, some basic database work (if needed), and some basic shopping cart/forum/blog setup done for them in this package. I typically provide two different design options for them to choose from. If they want to out beyond these items, then I start applying hourly rates based on the work.
More importantly, I also indicate the service available. They get free basic maintenance (simple page added, spelling corrections, not content block to the basic page) on the site as long as they are with me. There are plenty of outfits out there that will do things for a decent chunk less than what I'll charge, but they won't get the updates, they won't get the customized design decisions, and most importantly, they won't get the personal attention to their site they would want.
Those kind of features help justify a slightly higher price, and the fixed price allows the customer to not guess how much they are going to have to pay, which may make them try and nickel and dime your time away. You give them a solid product, at a solid price, and they can feel confident in that.