That depends upon a lot of factors such as where in the world you are located, what services you are looking for, which designer you are using, and whether they charge by the project or by the hour. Some only provide full service decorating and some might offer ala carte services.

$75 to $500 an hour, depending on if you purchase products through the designer. Consultations with no product purchase will be more of course. Or, like a contractor, a flat fee for the larger job as a whole, when you buy everything through them. Their labor fee is essentially capped in larger projects where someone allows them the freedom to design without being a control freak over every detail. Time is money to everyone in any business. The less decisive and clear you are about your needs, the more time and money you will spend on your project.