too good to be true?

[r4izuk0]

http://www.ebay.com/itm/Donkey-Kong-Land-3-Nintendo-Game-Boy-1997-NEW-/390284256871?pt=Video_Games_Games&hash=item5adec12667

In the past, I have bought a few sealed games from completely different sellers. When I got the items, the packages seems really light. So I go ahead and just open them, test them out, they turn out to be fakes. The prices I got really cheap. But its been years later and was wondering how to identify real from fake.

[soera]

That one looks legit. I see a horizontal seam and a plastic hang tab.