Let's use real numbers! :) Amazon current price $33.89, Price on Massdrop $18.49 + $8.25 domestic shipping = $26.74
This makes is $7.15 cheaper than Amazon, which I consider substantial.
DrNotSoHorribleAmazon didn't have it in stock under its own name when I made this post. When they run out, the price goes up considerably. At the time I checked, the price was $33.89. In reality, its a $49.99 msrp, so its a good deal at either venue.