Funko Pop! Premium HARD Plastic Protector Case for Regular size Funko Pop Boxed Figures $7.99 on Walmart.com (FREE Shipping if you order +$50)
If you elect to pick up in store it's $7.66 with pickup savings.
These are back on sale at Walmart, I always grab a couple when they are under
$8/each. I still see Groupon active for $46.99 for a 6 pack (7.83/ea) not as hot as pick up in store, but it does qualify for free shipping if you have some groupon bucks to use to make it sweeter.