I'm a bit confused on that part though, the offer says $15/hour, why did the author write as if the the offer was $3/hour? Isn't that the pay for manual data entry?
The price that she quoted him was $15. It's not clear that that was $15 an hour, or whether it was $15 for the entire job (regardless of how long it might take.) Considering that the writer questioned whether she thought it would only take him one hour to complete the task, that would be the way that I would be inclined to interpret the way it was taken (if not necessarily the way it was meant): Five hours work at three dollars an hour.