TomShop-US via Amazon offers the Tomshoo 180° Full-Face Snorkel Mask in several colors (pictured) for $36.99. (All colors are eligible, but only options fulfilled by Amazon are shipped from the U.S.) Coupon code "33EKYZIK" cuts that to $25.89. With free shipping, that's the lowest price we could find for such a mask shipped from the U.S. by $12. It features anti-fog and anti-leak technology. It's available in sizes S/M and L/XL.

Don't mind waiting? TomTop offers it in Blue/Large for $19.55 with free shipping; however, it ships from China and may take up to four weeks to arrive

Update: The price at Amazon now drops to $24.04 after coupon.