In that case (based on minimum wage in the US), either you're getting five dollars worth of quality, which is probably even less than this because this process allows extremely fast revisions, or the person doing it is getting massively underpaid. Or they live somewhere that cost-of-living and a typical wage are low enough that $5 for the work makes sense. Or they're using an automated system with an even lower cost-per-unit, which probably overlaps with the first possibility.