I am not practiced of this world, in your opinion which one is the best between these graphic card? Or a similar card.

Hello, I'm a new entry of this forum and I have a question.
I am starting mining scrypt but I don't know which graphical card is better.
The price is not important, I'm searching for someone that can help me to choose between these models:


Gigabyte GV-R928XOC-3GD - AMD r9 280x

Sapphire VAPOR-X R9 280X 3GB GDDR5 OC

Sapphire 11221-00-20G - AMD R9 280X

Sapphire Toxic - AMD R9 280X



I need to know which one is the best one for ratio Kh/Power Cost.

Thank you for the help