Amazon offers Prime members the Bushnell Bear Grylls 8x 25mm Compact Roof Prism Waterproof/Fogproof Binoculars, model no. 180825C, for $32.22 with free shipping. (Non-members can spend $35 or more to bag free shipping; otherwise it adds $5.58.) That's the lowest total price we could find by $8. They feature BaK-4 prisms, multi-coated optics, 8x magnification, and 25mm objective diameter.