$50 for 2000 words isn't bad by Upwork standards. I mean, I would consider taking that job. And I make a full time living on Upwork.
Getting started is the hardest part. I used to work for 1c a word sometimes, just to get some reviews. And I'm not too picky about what I write. Not if my name won't be on it. I look at it like any other job. If the client is happy, they got their money's worth.
I also write very, very fast. I'd take that 2000 word article in the hope of knocking it out in an hour. Two, tops. When you can do that, it starts to make sense.
Maybe this sounds mercenary. It is. Here on Medium, I write what I want to write and try to make something beautiful and worthwhile. On Upwork? I write what clients want and move on to the next project.