Walmart offers two Better Homes & Gardens 1-Piece QuickFit Outdoor Outlet Covers for $3.96. (You must order a minimum of two.) Opt for in-store pickup to avoid the $5.99 shipping charge. That's $9 under the best shipped price we could find for the quantity elsewhere, and at $1.98 per item, it's also an extremely low price for an outdoor outlet cover in general. Each weatherproof cover features an opening in the bottom for cords to fit through.
These freebies are available to anyone with an internet connection, including both Amazon Prime members and nonmembers.