For non-Prime members, the minimum order for free shipping was $49. Amazon lowered it to $35 for non-book items. More on CNET:
https://www.cnet.com/news/amazon-lowers-free-shipping-minimum-to-35-from-49-matches-walmart/
https://www.cnet.com/news/amazon-lowers-free-shipping-minimum-to-35-from-49-matches-walmart/