Why do all U/U items sell for 1 gil?

[Mychael]

If my dear Elezen girl is coming from where I think she's coming from, then she's talking about turning gear into a certificate on the spot, a certificate that would be Untradeable with a x/99 stack or a key item of sorts. At least, that's how I look at it.

Not what I got.

Get a certificate from GC so that any time a second U/U item is dropped into your inventory it immediately gets transformed into seals rather than being lost.

However, what you suggested about duplicate items turning into certificates sounds much better. ^-^