Honestly, I think you are better off buying from Amazon. At least they are reputable just in case something happens to the pump. We all know these Jebao DC pumps will not last long I'm on my second DC3000 and super glad I got the first one from Amazon.
If it was like a sicce, tunze, or Eheim then I can totally understand the value in the saving but you might end up with a $50 paperweight with these pumps after a couple years if you're lucky they even last that long
Also Make sure you buy from Amazon, not a store that sells on Amazon. The warranty and customer service, which you really need in this case, are totally different.