I figured that for the new player both red necklaces would should up: one for 7,000 and the current one for 20,000. Maybe that's not the case?

Regardless, since the jewelry buff from necklace and earring appears the same - can it be applied twice?

I see both Red Necklaces (7k and 20k). I already bought the 7k one, so that shows up at the bottom.