How are you doing copywriting (SEO/agency)

Hi, I'm starting to think about having my own growth marketing/SEO/SEM agency/freelancing. And I was wondering as a one person team at first. How do you handle blog copywriting for clients when it comes to SEO? I don't do copywriting, and this is extremely important as you know. Do you hire on platforms like fiver/Upwork? Also, if anyone can help. What would be the typical prices for this? X amount of words/blog post. Etc