Like most of you, we develop themes, making almost a full cycle: from HTML versions to different CMS variations: WordPress, Magento, OpenCart. However, it is not always possible to implement all our ideas without the help of third-party developers, additional applications, components and plugins. This increases the cost of the final product.
So I have an offer to collect in this topic all possible applications and plugins which can be used free for commercial purposes, that finally will reduce the cost of our templates.
I think that I understand you.
you don’t need buy a plugin, you can download plugin free but link plugin when you end make website virtuemart, wordpress, etc you can add link item where you can download free plugin and also documentation.
I don’t sure I think that you need permission other author of plugin for download free.
I hope help you, regards.
p.s: you can wait other author help you because I know good themeforset but don’t 100% because I never upload my themes themeforset, I go to first sell themes themeforset
Edit: I don’t speak very good my english, I speak spanish only.