I have setup a monitor on this page using Monitoro [1] and it will send me an alert when the corn is not "sold out" anymore.
Disclaimer, I'm the founder of Monitoro, you can sign up here [2]. And feel free to reach out if you need any help.
[0]: https://store.experimentalfarmnetwork.org/collections/grains...
[1]: https://www.youtube.com/watch?v=050Y6NSIu6I
[2]: https://monitoro.co
https://www.ebay.com/sch/i.html?_nkw=nitrogen+fixing+corn
No idea if legit.