Some items don't make sense.

[Antipika]

Regarding rose gold, it's a matter of how much gold is present, in proportion of copper/silver. You cannot tell how "fine" the rose gold and the electrum are. Silver is roughly 50 times less valuable than gold. While copper virtually worth nothing in comparison.

Rose Gold is typically 75% gold / 25% copper. (18K) [It's a matter of color, so it cannot vary too much or you won't obtain something "rose"]
Electrum ranges from 40% to 90%. (With a lot of historical examples showing something close to 50%/50%) [No set rules on how much silver should be in there to be called electrum / no color requirement either]

Do the maths, now you understand why Rose Gold can be more expensive.

Edit: Punainen said the same while I was replying :d