1020 is the one to get if camera is the biggest draw.
Next best Lumia phones for camera is the 1520 and Icon. The 920 is long in the tooth now spec wise and I don't believe it is worth $270. Under $200 (unlocked), maybe.
Agreed. $270 is a bit high for a phone that old...especially when phones less than a year old often pop up for under $200 refurb and unlocked (recently both the HTC 8X and Lumia 928 were showing for under $200 at various sites).