Having worked with a fair few brands on explainer videos, I'd say the sane middle ground for a proper 60-second piece usually sits somewhere in the low-to-mid five figures. Not eight hundred bucks, and not necessarily forty grand. What drives the cost is usually script development, custom illustration, animation complexity, voiceover, revision rounds, and whether they're doing genuine concept work or just executing your brief.
The cheap option can be fine for testing a message quickly, but it's often template-heavy and stingy with revisions. the agency version might bundle in strategy, stakeholder hand-holding, and polish, but you're also paying for their overheads and layers of approval.
the smarter path, in my experience, is to split the process. Get the script and storyboard nailed down internally or with a dedicated copy specialist first, then bring in a strong motion designer or small studio purely for production. That way you keep quality high without turning the whole thing into an agency science experiment.