If I wanted to use a US content store and in fact lived in the US (which sounds like a prerequisite for being able to enjoy those Costco discounts), presumably I would not need to purchase gift cards in the first place.
Where gift cards are available, they are never cheaper than face value due to basic market dynamics.
In retail stores in non-Western countries I have never seen a gift card with e.g. 100 unit value sold for less than 100 units either, although I haven’t specifically looked for such.
I didn't say you could go to Costco. Just that the market often values gift cards at less than par, because they are generally less useful than normal money.
In degenerate cases, I can see that the reverse could be true.
Where gift cards are available, they are never cheaper than face value due to basic market dynamics.
In retail stores in non-Western countries I have never seen a gift card with e.g. 100 unit value sold for less than 100 units either, although I haven’t specifically looked for such.