What these costs look like at scale
At four posts per month — a modest but consistent publishing pace — freelancer-rate production runs $660–$1,260/month, or $7,920–$15,120/year. At eight posts per month, the same math produces $1,120–$2,320/month, or $13,440–$27,840/year. At twelve posts per month, you're looking at $1,580–$3,380/month, or $18,960–$40,560/year. These are the numbers before management overhead.
Agency rates at the same volumes are roughly 2.5–3× higher. Eight posts/month at agency rates: $3,500–$5,600/month, or $42,000–$67,200/year. This is consistent with what most mid-market companies report paying for content retainers — the headline number in the contract usually lands between $3,000 and $6,000/month for meaningful volume, and that tracks.
The hidden kicker is management overhead. Agency relationships require significant internal time: briefing sessions, review rounds, feedback cycles, brand alignment corrections, and the occasional full restart when a writer turns over. Industry research consistently puts this overhead at 40–60% of the explicit production cost. A $48,000/year retainer often carries $18,000–$28,000 of internal management time on top. The total investment is closer to $65,000–$75,000/year — and that's before you factor in the 2–3 week cycle time that means you're always 14 days behind what you wanted to publish.