All of these episodes have been preserved online, see for example: https://archive.org/details/jre-001-837

So there's not really a need to 'save' them.

Also if you want to crowdfund something there's much better ways to do it than an NTF, though in this case it's unclear that you need to do any kind of funding because people are can just donate time.

Most NFT don't save the content of the image/audio/text whatever in the blockchain. Most don't even save a hash of the content to ensure what they are pointing too. They only save an URL that will show you the content, or whatever the owner of the URL wants to show you.

It is possible to store the content of the audio files in the blockchain, but it will be very expensive. Storing the transcript would be expensive, but not so expensive.

I'm not sure how a NFT would be useful here. If you split the talk, perhaps someone can buy the NFT that point to the fist minute, and then only listen to it???

How would an NFT help preserve a large binary like a JRE episode?