What? That seems crazy to me. You would literally turn away people that want to add value to the FOSS foundational ecosystem, which in turn brings in contributors and donations to keep things going?
Also this seems to be a confusion about what FOSS is. FOSS "freedom" isn't about "free as in beer", it's about "free as in speech." The GPL even welcomes commercial software, provided they include the source. I'd be thrilled to see a category of "paid FOSS" in the store, and I'd buy quite a bit of it if prices are reasonable and the software is useful.