For original lyrics that do not require any research, or if I know how to write like a given artist of a particular style, I ask 10$US/hour. If research is required (if you ask that I write like a particular artist), then I ask 20$/hour for the added time it takes to immerse myself with a style I am not familiar with. Usually, 2 hours are enough to complete standard length lyrics.
If all the necessary references are provided, and I know how long to make the lyrics, then it usually takes only a few hours to write professional lyrics. But oftentimes, I have many more lyrics to write, so I require some time to make sure I write the best lyrics possible.
Corrections after delivery
I will offer 2 revisions at no cost, after which the standard rates will apply. Usually, though, all my past customers have always been satisfied with the lyrics I wrote for them on the first try, with only a few ever asking me for a revision of a part of verse due to reasons they did not mention before I started writing their lyrics.