Meritline offers this ABS Batman Face Mask
in Black for $2.99
with free shipping
. (homegarden center via eBay
offers it for a few pennies more.) That's tied with our mention from last Halloween as the lowest total price we could find for a comparable mask by $10. It measures roughly 9" x 6" x 2" and features an elastic band.
Expect this item to take two to three weeks to arrive.