'Kowaltowski is one of countless researchers who report they’re too strapped to pay these article-processing charges (APCs), which can reach more than $12,000 per paper and are becoming the dominant business model for scientific publishing. Publishers tout fee waivers or discounts for researchers in need—but obtaining them is cumbersome, authors say. That’s a worry especially in the Global South, but even some authors in wealthier countries say they end up paying APCs from their own pockets.'
https://www.science.org/content/article/pay-publish-model-open-access-pricing-scientists