Well, it depends. There are some writers who provide you good quality in $0.01 even, but not always. On the other hand, magazine quality definitely demands good amount, and writers I know charge between $0.1 to $0.4/word. Copywriting section can have best answers, I think!
As a content producer, I'd say that the price you pay is largely based on how you define "quality." If, by "quality" you want your topics to be heavily researched, extremely well written and to accomplish a specific goal (say to sell an affiliate product or attract traffic) it is going to cost you more money than a quickly written article that simply fills space on a website. For example, I can write a short article (say 200-300 words) for $5--but for $5, you are likely to get something quick and "place holdey." For $25 or higher however, I would be more likely to put some time into the project--research the topic thoroughly, do more than one or two drafts, spend more time on edits, etc. I'd also be more receptive to things like rewrites and changes. What do you want your content to do? Do you simply want to fill some web space or do you want your content to drive your sales, build your reputation, raise your rankings in the search engines? Another thing I want to say (and then I'll stop typing because this post is getting long) is that you might cringe at the idea of spending a larger amount of money right now, but it is better to pay more for quality content now than to pay a low amount and then later have to pay someone else to rewrite it! Incidentally I'm hireable