A little light is shed on when and how much the Lumia 920/820 will go for.
Nokia Germany put out a Press Release stating that the both phones will go on sale in November and will be priced at 649 euros ($836) for the Lumia920 and a cheaper 499 euros ($643) for the Lumia820. You might say that's pretty pricey given the SGSIII is around $500-$600 range (but that's plastic).
Though the phones will be available through carrier operators, so expect to pay much much less if you want one from your telecom operator on contract.
In Italy too, Nokia also revealed that the handsets will be available in Novemeber, but their prices are cheaper compared to Germany's. the Lumia 920 will go for €599 ($771).
Nokia Russia also put out a press statement on availability of both phones, Lumia 920 will sell for 24,990 rubles ($803), while the Lumia 820 will go for 19,990 rubles ($642), the press statement also says the phone will be available in the Q4 2012, seems like a November release too!
In Austraila, both Lumia 920/820 will be available via major phone carriers: Telstra, Vodafone and Optus, but price and available haven't been announced but are said to at the end of October, leaving the strong assumption of a November release also,
Except more official word for availability in more Europe countries in the coming weeks.