I have been with writers hub since January this years and I could say it is among the best site to work with, however you have to be a good writer to work efficiently with them. I am a senior writer currently, and I get paid some good amount of money. So its up to the writer not the company. But I could suggest, they increase the cost per page to start even from $3.5 as this will satisfy most writers.
Dear Ferdinand,
We are glad to hear that you enjoy working on our platform!
As for price per page, apart from the basic salary for each order, we offer extra bonuses due to the good performance.
You may contact your account manager to inquire about them, they will be glad to provide some useful information on how to earn or increase your bonuses.