There is nothing to keep paying for
A subscription makes sense when the developer has a bill that comes round every month: servers, sync, storage. SSPaste has none of those. Your clipboard history is a database in a folder on your Mac. There is no account, and nothing is uploaded. With no running cost on my side, I could not find a reason to charge every month.
What the price does not buy
The same decision has a cost, and it is better said here than discovered in a review. No servers means no sync. SSPaste lives on one Mac and has no iPhone or iPad app. If you want what you copied on your phone to turn up on your Mac, this is the wrong tool. Paste does that, by subscription or for $99.99 once.
What is free, and why
History is unlimited in the free version, in the tray and in the popover beside your pointer, together with search, a Favorites Space and backups. The first plan was different: the free version would hide anything older than seven days. But macOS already has a clipboard history of its own that keeps up to seven days, and Maccy has long been free. A free version that did no more than the system would have given nobody a reason to install it.
So Pro sells organising, not remembering: more Spaces, the Private Space, the library with its canvas, finding pictures by the text in them, and typed words that turn into filters.
How the trial ends
Pro has a 14-day trial that you start yourself, and nothing is charged when it ends. If you do not buy, the Spaces and the Private Space you made can still be opened, pasted from and exported. You cannot add to them or change them, and the canvas is unavailable. Your clipboard history is not affected.
Where to find the price
It is $9.99 in US dollars, and the App Store will show it in your currency. SSPaste is not on the Mac App Store yet. The pricing section lists what is free and what Pro adds.