Those sites are garbage and there's several hints:
Banner across the top that follows you (don't know why, they all do this though)
Generic "about us"
Street address not associated with a real business (in this case a random home address)
Limited history on archive.org - this is a big one, website created within the past year.
I would say that the prices raise an eyebrow, but part of the problem is that sometimes they're savvy enough to make them believable but tempting.
This "style" of site is super common, and they've figured out how to game Google search results so that they show up as "product" listings alongside legitimate retailers like Amain and Hobbyking. You can immediately recognize them once you've seen a few.
Here's another thread about the same kind of site and problem.
They gradually wise up, adding one or two more convincing details, so eventually there will be fake sites that pass all the criteria I've listed.
