But will they still get future updates? It's entirely possible possible that I'm just misreading it, but there's conflicting information that's not really helping. The Pricing page on Itch says you're free to change the price and people will retain ownership, but it doesn't specify anything about future updates.
From another dev (paraphrased from what I remember): "I can tell you think of a price and stick with it throughout development. I found this out the hard way when Itch blamed me for raising my price and said it was why people couldn't access the latest update."
files with special prices
This is what I though and understood the first time as well. The way you phrased it. That you can buy the files. You can't. Your payment level of your purchased project, that you now own in your library, is compared to the payment level of the files when trying to download. This does not affect updates in any way. Except if one would set a different level for new files.
Maybe this is a translation issue. But I think this is very ambigous in English as well.
Imho it is less of an abuse and more of a problematic feature design and naming.
There is a pricing feature that is called individually priced files.
It basically is causing a lot of confusion and no one uses it "correctly", since there is no clear cut use case. The biggest problem is, that a buyer cannot increase the payment level. So if you have a 10 $ file and someone paid 10, they can access it. If you have yet another file on that project that is 20 $, they cannot access it. But they also cannot access it, if they pay another 10 $.
Since Itch has no dlc mechanisms that I know of, people use it for dlc. But as explained above, it is quite frustrating and misleading for that scenario. Or they use it to have a public and a paid version on one project page. The "demo" mechanism would be misleading here, since a public version is a complete game, and a demo is a very restricted portion of a game. If you have a free game, you maybe want to be seen among the free games for advertising. But you also want to offer your upgraded version as a sort of dlc or just like you see all those apps on mobile platform where you have the in-app purchase method to upgrade it.
At the very least Itch should make it impossible to have more than one level of "individually" priced files. Even the term is misleading. It sounds like you can buy the files individually. Or fix it, that you can upgrade your level. Or generally overhaul the feature.
So if that dev you spoke of used that feature to implement a minimum price and raised that later, yes, people will not have access to the higher price tier. He should have made that price level the minimum price and ditch the individual pricing scheme. So anyone that paid any amount previosly would have access to all current files and future updates.
