This catalogue distinguishes five price models. Side by side in the filter they look alike, and they mean very different things — above all for the question of what still works in five years.

Free

Usable without paying. That says nothing about the source code and little about the future: a free plugin can be closed, can require an account, can collect data, or can cost money in its next version.

Open source

The source code is public and may be reused under a licence. Almost always such a thing is free as well, but one does not follow from the other.

The practical difference shows when the maker stops: an open-source tool can be maintained by somebody else; a closed one is gone with the next operating-system update.

Purchase

Pay once, use indefinitely. The usual catch is in the small print: upgrades to a new major version often cost again. What a purchase includes — a year of updates, all updates, none at all — is decided by the maker, not by the price model.

Subscription

A running payment for use. The decisive point, and it only shows up late: when the payment stops, access usually stops. Somebody who stops paying after three years may no longer be able to open old projects — not because the files are gone, but because the plugin will not load.

Against that stands a real advantage: no large sum at once, and updates are included.

Rent-to-own

Instalments leading to ownership: you pay monthly and own the licence once the full price is reached. Stop before that and the money is gone.

The difference from a subscription is the important one — finishing leaves you something. The difference from a purchase matters too: all told you usually pay somewhat more than buying outright.

The one question worth asking

Not "what does it cost?" but "what happens when I stop paying?" With purchase, rent-to-own (paid through), free and open source: nothing. With a subscription: possibly access to your own work.

That is not an argument against subscriptions — it is an argument for knowing the answer beforehand.