7 per line is the lowest you get paid and to get that you have to send more than 10% of your work in for blanks. The next tier is 8 per line and there is the potential to earn more based on quality metrics.
The absolute lowest I would be willing work for is probably in the 12 to 13 per line if you are taking on all the work and responsibility yourself, especially if you will be required to provide back-up should you go on vacation, etc.