I was just looking for the open source Cyberduck utility. I thought I'd start on the Apple App Store, but there this free app is 21,49€!

If I go to the home page it is free to download and I can donate if I want to... There is also a link to the App Store to download it for a fee... Colour me confused.

There are plenty of free apps in the app store. If the app store entry is legit it's charged for because they told Apple they wanted to charge for it. Either that or the app store listing has been put up by someone else entirely, in which case it would be up to the Cyberduck people to tell Apple to take it down.

The default security for later OSes is to only allow downloads from the App store and other trusted sources. So for many people they might not realise that they can get it for free/donation.

Dave: http://cyberduck.en.softonic.com/mac
Free.

It is also free to download from their homepage, but there is a link to the store there as well, which is 21€.

Worth shooting an email to the developers to see how they're justifying it then?

They could easily justify it as a way of raising funds to pay for development. You could still use the free version and make a donation of the same amount.

The App Store probably has rules about "donation-ware". You either charge or offer it for free. There's no option for a middle ground (ie no trials are allowed, and no full feature activation by an IAP either), so I expect this is the best choice they have.

If there is a non App Store version of an app, always go for that option anyway. There are restrictions and sandbox requirements on the App Store, and some apps have features that are disabled or hobbled because of these restrictions. BBEdit is one for example.

Sandboxing works for a lot of apps, but anything that digs deeper into the system (ie using command line utilities, or accessing AppleScript) may be hobbled or not allowed.

There is also the delay in apps being updated on the store. 1Password is sometimes as much as three updates out of date before a new version appears.

That is one thing I like about the Windows App stores. You download a paid for app in trial mode and you can either use it for a limited time or with limited functionality. If you like it or it fulfils your needs, you can pay for it and unlock the full functionality. You don't clog up you account with light and full versions of the same app.