Guest post rates can vary depending on a number of factors, including the publication's audience size, reach, and authority; the length and complexity of the article; the amount of research required; and the writer's level of experience. That said, there are some general guidelines you can follow when setting your rate. For example, if you're writing for a small blog with a limited reach, you might charge $50-$100 per article. For a medium-sized website or blog with a moderate audience, you might charge $100-$200. And for a large website or blog with a wide reach, you might charge $200-$500 or more. Of course, these are just guidelines - ultimately, the decision of how much to charge is up to you. But by considering the factors mentioned above, you can come up with a fair rate that meets both your needs and those of your client.