Casper mattresses are up to $183.61 cheaper on Amazon than Casper's site &8212;&160;even *after* Casper's 10% off sale

Casper is possibly the biggest home-related buzzword on the internet right now. The pioneer of the mattress-in-a-box trend doesn't do sales often (because they don't need to), but it's offering 10% off this week in honor of Casper's 10th birthday. Aw.

That seems like a steal until you realize that Amazon is literally celebrating Casper's birthday harder than the company is: Making your purchase on Amazon can save you up to an extra $183.61 compared to Casper's sale prices — plus Prime shipping.

For example, adding a queen-sized Essential mattress to your cart and using code SPRINKLE on Casper's site brings the price to $715.50 (originally $795)On Amazon, a queen-sized Essential mattress goes for $600 flat.  Read more...