Amazon has this Black Neoprene Half-Face Ski-Mask for $1.24 with FREE shipping.
My son has this mask and loves it because it allows him to wear his own hat and still have protection. Plus if he gets hot, he can just lower/remove the bottom part and still have his hat.
This is probably going to take a FAIR AMOUNT OF TIME to ship, so order now and get it for the first snow storm.
Pricing was current when the post was published, however Amazon prices change often, so please check before you buy.