FWIW this is in the normal range for what a good blog post costs any business. My first job paid me $50 per blog post and I churned out a few a week. My second job did $1,000 for three very high quality ones per quarter. (Blogging is no where near my day to day job).
All were just posted on the corporate blog for seo, building the brand as experts, etc. One of my posts was reblogged by some major outlets, so definitely worth the cost for my employer.