It's only normal for open access journals to charge (or making a paper in a traditional journal open-acess), as the journals cannot sell access to the article.

It's only normal for open access journals to charge (or making a paper in a traditional journal open-acess), as the journals cannot sell access to the article. And the fees are usually a few thousand. Of course it's also most common for "predatory" journals to be open access and charge thousands.