I am a full time independent contractor for a literary agency. I essentially review literary materials and submissions for representation and write up coverage reports for my bosses or sometimes for the writers themselves. I am paid per submission, to do as many per week as I can manage. I started as an intern there doing something very similar, I then signed a non compete to do this work for pay and receive a 1099. Being painfully naive back then, I did not request alterations to the contract I signed, so I doubt I could do this same work for anyone else. I have been paid the same rate for over three years, during which time I am certain I have had more submissions than any of my fellow contractors. I have been treated very, very well, my input has always been praised, and whatever I can and cannot do within my given time has ALWAYS been okay. I know my efforts are valued.
However, I am at an impasse and I need to evolve; I need to make more money. To be fair, I have NO IDEA if anyone else who is doing the same work is being paid more than I am, I just know those who can only intermittently do submissions have a standard of 50 per, and those who are available to keep up with the consistent rate of submission are usually paid 65, like me. I don't know if anyone has negotiated anything higher privately. Is it fair to ask for more money in this case, or should I look for a new position in the same field? I sense that there are simple standard fees for such work, and worry that it might not be my place to ask my bosses to pay me more without actual promotion of position.
Whatever I do next, I could use some advice on how to best approach it with utmost professionalism.