Making it free is usually an excuse to fail. Failing is easier than asking people for money.
My idea is build a supplement store that allows discovery based on science, rather than marketing. You can search supplements based on their ingredients and see them in the context of research papers about it.
I am curious how this translates to what you are suggesting.
And maybe you have solved all the real problems of inventory and cash flow and shipping and buying already.
Because you don’t need a different approach to sell supplements. Doing what everyone else does is a known solution. But it is harder than building a website.