I see roughly the same thing:

Your post says there is a podcast at [url] and that you are working on a guide as a companion to it, but it doesn’t say anything about where the guide is or whether any of it is online yet at all. Ok, I see now that the link url is discuss.james.network which is a different domain than the podcast, but that is still not much help. If that’s where the guide is, you should say so. I’d expect to see a discussion forum on a domain like that, not a podcast transcript.

Really, though you should just include the guide in the post. Otherwise you’re just promoting your podcast and discussion site.

You should explain that in the post body, not expect someone to click a link that says “podcast” in hope of getting a non-podcast.

Doing something like this “for real” on any scale takes a ton of anti-spam and anti-fraud effort. Look at how big a pain it has become to post on Craigslist, which doesn’t even do commerce directly.

On a small scale it’s less of a big deal. If you want an actual sales and payments platform like Etsy, it would have to be done by an organization of comparable scope, even if offloading payments to Stripe or whatever. Lots of seller vetting, dispute resolution, etc. I don’t think it’s impossible but it’s not just a matter of software. It would need paid staff dealing with hassles all day, imho.

The link is to podcast.james.network. Why would I expect it to be something other than a podcast?

Flohmarkt is German for “flea market” so I’d expect something along those lines.

I see, you are trying to make a home theater PC (HTPC). That would be a clearer term to use.

What does this question even mean (no I don’t want to listen to a podcast to find out)?

Sometimes I think people have been using the term “self-hosted” to mean what we used to call a home PC. I have always thought of a hosted computer (whether self-hosted or hosted by a company) as meaning a server which normally would live in a data center, and sometimes even means a rented box or VPS on which you self-host by installing and managing the software yourself (as opposed to using managed hosting or cloud services). Of course if you have good enough internet, you can self-host a server at home, but the considerations are otherwise about the same. I.e. it would usually not also be your workstation or gaming box.

So what is it that your friends are going to do with the machine? That would be pretty important in figuring out how to prepare it.