I wouldn't expect Costco to pass fake bars (knowingly or unknowingly). But when you go to sell those bars, you're just some guy with gold bars, and how does your potential buyer know you can be trusted? I mean, you could show your receipts from Costco, but how do you prove that you haven't swapped out the good bars for fakes?Maybe a knowledgeable-enough buyer can distinguish fake bars as reliably as fake coins. To me, though, coins are easier to authenticate, and that makes them easier to move.
Of course, if you never intend to sell your gold, that probably doesn't matter. But in that case, does it really matter whether the gold is real in the first place? After all, a fake bar that you believe is real gives you the same tingly feeling as a real one...
