HTC added a new color option to the HTC One palette Gold. Not actual gold like the limited edition One mind you. Anyway, just two days after the announcement, the first carrier to offer the phone has already stepped up.
O2 Germany has exclusivity on the Gold HTC One in the country. On contract the phone costs the same as the other color versions (again, it's not real gold). It's a symbolic 1 with 40/month deal for two years.
Off contract, the phone is 540. You can find an HTC One for 460 on Amazon.de, but there's no Gold option, of course. Also that price is for the silver version, the most expensive version Blue is 510.
The Gold color option of the HTC One should launch in other countries soon too, but there's no official info from any other carriers just yet.