Im looking for :
- A native English speaker (ideally, from the US)
More informations :
- I estimate that you will need between 3 and 4 hours to complete the job
- [...]
- I will pay you the equivalent of 15$ in bitcoins (for a job well done!)
Unskilled workers can make ~$8/hour flipping burgers at McDonalds. This kind of worker will probably not do a very good job, and probably wont be able to catch all your mistakes.
More skilled workers are going to command a higher wage.
If you increase your offer then you will have a better chance of finding someone capable of doing what you need done, especially considering that you are looking for a native English speaker.
You are free to offer however much you wish, however I would suggest offering between $40 and $60 for four hours of work.