You might use the RX 470 for the Ethereum mining. It will be on sale in the next two to three weeks.

The RX 470 is on sale now. The price is around $200. It seems the memory bandwidth is 256 bit, same as 480.

Somebody on the forum said you cannot overclock the memory speed, so it might not be the good card for mining ETH.

I heard the BIOS is locked, the memory frequency is just 1800 for the 4GB cards. So hash rate is low.

You can modify the BIOS with BIOS editing tools. For example, you can raise the memory limit to 2000MHz or higher.