Amazon gives non-Prime members free shipping at $35 or more of eligible items. Instead of simply letting users get the product with free shipping, they’ve added a discount that prices it exactly one cent below the $35 limit, while only subsidizing the price with $3.38, which is about half of what they’ll then charge you for shipping.
Yes, I try to buy things second hand but if it’s not possible to get it that way I usually resort to one of the local stores or AliExpress.