I know you can't use starter and training etc.. assets made by Unity for commercial purposes, but according to this every Unity asset made by Unity is restricted for commercial use. So that means I can't use Post Processing Stack? That would be disappointing.
Re-reading the page you linked to, we can see that you can use the assets from the assets store in a commercial game.
You can purchase assets from the Asset Store and use them personally and commercially in your game.
Once you have purchased an asset from the store, it becomes yours to do with as you like within your games and apps. You will be able to use them in your game for commercial use with no extra payments.
Now, as you mention Restricted, so here is what is says about restricted:
Unity "Restricted Assets" are subject to restrictions that others are not. These are only valid for personal and non-commercial use only. No other use is permitted, and these Unity assets must not be used in your commercial games.
This means that Restricted Assets can't be used in your commercial game, while others can, paid or not.
Since there is no "license" sections on these Assets Store pages, it's a bit hard to know at a glance which one is a Restricted Asset, and which one is not. Searching around, you'll notice that the restriction is written in the asset description. You can see a couple examples searching via Google.