Is there an audio course, that busy people can use to learn Esperanto from scratch from anywhere? I am looking for something like Coffee Break Spanish, where a speaker uses a start language (here English) to teach a goal language (here Spanish). As the episodes go on, more and more words are in the goal language instead of the start language.
The Assimil Esperanto course is an audio-based course, albeit with an accompanying handbook which I think is only in French. It's available via Amazon for €39: https://www.amazon.fr/dp/B00008CTCE
This is a great idea. I can't say that I have ever heard of such a course. The closest I have in my collection is Flugu kun Petro - a rather "home made" looking course for children that includes crude recordings of the text in the book.
A quick Google search turned up this blog post which recommends Jen Nia Mondo.
The above link also mentions a course by Sylvan Zaft in podcast format, but the link was broken and I was unable to locate it.