This journal — and the other journals published by Online-Journals.org — are out of scope for my work because they are not, by definition, open access.
One has to register to view the published articles. This additional barrier to viewing the articles means few will see them, and anyone who publishes here will be hiding his work, for the most part.
If you want to pay to publish in an open-access journal, you would probably be better off not selecting one where readers have to register to view the articles.