First, this is an AMAZING resource from Search Engine Land. Smart content writers do WAY more than putting words on a page.
Other things to consider are: Do you find their writing engaging? How does their writing position?
What “level” of freelancer do you need – someone who is newer to the game? Years of experience, so they can help you with other things besides the writing? Do they have industry expertise?
Here’s a big one. Does the writer “get” your brand and your company? That « click” is so important.
As with other things, you get what you pay for. You don’t have to pay top $$ for every piece of content, but good writing costs money. Paying $50 for 1,500 words probably isn’t going to get you the best content. Sales content can be $$$, too.