Separately, and so in its own message, I have questions about the pricing page. It seems like the two options are the Sandbox, which is "for personal projects", and Pro, which is $1,850 a month and for "production workflows". Am I understanding right that to use Prefect Cloud (i.e. without deploying it ourselves) in a production setting where potentially many workflows are running daily, we're looking at entrypoint pricing of $1,850 a month?

Yep - the cheapest paid entrypoint is $1850. YMMV, but IME Sandbox was good enough to run my last startup on for awhile, executing a few hundred workflows a day. It doesn't have any governance stuff, but on the orchestration side it's more or less the same feature set with a different rate limit.