The rates for copywriting work vary according to the type of copy being written and the individual supplying the copy. For example a client living in Newcastle is likely to pay less for a local copywriter than someone who lives in London, this can work to your advantage though as many companies situated in the capital will outsource their work to copywriters where the cost of living, and therefore the hourly rate, is lower.
The majority of copywriters will tell you their rates if you ask them nicely, use the Internet and Yellow pages to find companies offering the same services you plan to and drop them an email or telephone them to find out. Freelance bidding sites and sites of individual copywriters show anything from �10 - �50 per hour, some also charge by the day or prefer to price a job as a single cost.