For example, I use different google search operators
I check Website authority
Backlinks: If website looks suspicious i check more detail in backlink profile.
I check if website has some strong backlinks from other websites with bigger authority.
Organic traffic: The website must have Organic traffic to look real
I have a website https://www.ourhairstyle.com/write-for-us/
So I usually get a 3-5 /week outreach offer from other editors.
So I understand how person psychology works, how to get a better price.