Adidas Swimwear $15 inc. shipping.

https://adidasswimming.com/pages/sales
Men’s Swim Briefs and Jammers
Women’s Elemental Raw Vortex Back Swimsuits
Lots of sizes at the time of posting.
Final sale.
Note: Everything is $5, but shipping adds $10, so I put the total price in the header.
Clarification: the shipping appears to be flat rate, so the max you can pay for an item is $15. If, for example, you buy 5 items you’d pay $7 per item including shipping.