I charge for development of (F)OSS. It's my salary. My employer likewise charges the patrons/funding agencies. But we get paid once for the effort, like any usual labor contract. We don't try to get paid again when our past work products are copied.

In the old days, paying a distribution cost was more common for free software, when it actually took effort such as writing and shipping media. This handled the case where someone asked for a distribution, so that sharing did not become a financial burden. It's a mostly obsolete concept now with pervasive internet and many low cost or free hosting options to put content out there at essentially zero marginal cost to deliver copies.