Amazon offers Prime members the Fruit of the Loom Men's Jersey Knit Sleep Pants
in Black, Grey, or Navy from
with free shipping
. (Non-members can spend $35 to qualify for free shipping; otherwise, shipping costs $5.48.) That's the lowest total price we could find by $9. It's available in sizes S to XL, with price varying by size/color combination.
Of note, some sizes are available for slightly less with purchases of $25 or more via Amazon's add-on program.