Author of Symbolica here: for your personal projects the cost is 0, as you'd be a hobbyist.

Symbolica is developed by only one person, so forgive me if I can't get every aspect of the project right on the first try (especially the non-technical part) :) I will see about removing the online on start-up part. It's essentially the only anti-piracy step that I have.

At the moment there is no fixed cost for use in industry, since the price will vary based on the amount of users and other factors.

I don't mean to belittle your great achievement with license annoyances so forgive me if this sounds harsh, but I won't look twice at any software with an online requirement, if internet connectivity is not an integral part of the software itself. I do realise open source can be a dark, unthankful place that will not pay bills for most developers so this is not about the cost itself.

Unfortunately, pirates almost always have it easier than paying customers, since license checks will probably be removed. Though this is hearsay (anyone?), there was "legal piracy" (no, there's no such thing :P) in the license-via-printer-port-dongle-era, since the dongles sometimes failed at the worst of times (e.g. live recording at a studio). So some users/studios bought a license to be legally covered on paper, but used a pirated version.

I live in a "well-connected" country, but a traveling a few kilometers in the wrong direction leaves me in complete radio silence, and sometimes work (academia) has required me to stay at such places for a couple of days. Since you know Rust, I can (and have had the need to) add `--offline` when building, with required crates locally cached. I know many researchers with the need to bring high-tech equipment + software to remote locations for work over many weeks, sometimes months. The need to find a city just to do a software license check would be crazy.

Unfortunately, I also don't have a good solution, other than trying to trust your customers. An online check once, at install, I can possibly live with, even if I've had to do reinstalls from local files in the field as well...

He's already said the fee for you is 0. It seems he's mostly going for the university side wide licenses, I don't think issues such as yours are very important for him.

Most people at a university who want to run a computation for a few days will do it on a computer that's permanently connected to the net, I think. Not their laptop.

Give people a ballpark single user price, and a note that discounts can be given for multiple users etc. If you don’t quote any price the assumption will be, “if you have to ask you can’t afford it.”

That's probably how it is. Given that he sells only academic licenses, if he sells 3 site licenses for €6000 each, that's a salary (a low one, but you can actually live from it).

If he advertises a single-user license for €200, let's say, then each site has to have at least 30 users to make the same kind of money. Unlikely each current site has that many users, so it doesn't make sense to offer single-user licenses if there is the danger that sites will jump to that.