$1/week is a lot for what a single author could put out. If you take into account time researching, I can't imagine that would amount to more an article per week at any kind of quality?
Let's say you have 40k readers and 50/50 overhead vs writers. So, 40k people pay 1$ and get to read the output from ~10 writers. Now, get another ~2k people to sign up and that just about covers another author assuming your overhead does not increase.
Clearly, you can play with these numbers with various assumptions and readerships. But, the point is you can scale things down with paid subscribers.
