This is just my suggestion.. better to build a set manually not to buy already a cpu or desktop because if you build your own you can save..
Try here maybe you can get some idea here https://www.cryptocompare.com/mining/guides/how-to-build-an-ethereum-mining-rig/
thanks alot for reply bro, and u helped me alot, i have more questions
some of my friend selling this card Msi twin frozer r9 280x 3gb at 150$ http://www.amazon.in/MSI-R9-280X-GAMING-3G/dp/B00G64H1JW?tag=googinhydr18418-21&tag=googinkenshoo-21&ascsubtag=46361708-1bd7-4010-9b87-b486c92a904d
how much power it generate?
and some more questions in this link https://www.cryptocompare.com/mining/guides/how-to-build-an-ethereum-mining-rig nothing mention about processor which processor will best?
and can i install diffrent gpus? like 270x 280x in same system?
and with this system can i mine other coins too? or just its for only ETH coin?
You can mine all coins you want but it is profitable thats is it , you can mine X11, X13 ,X15, LBRY , ETH , ETC, CryptoNote,Nist5 ,Qubit ,Quark, X11evo, you only need the spec. Miner for the algo
I mine with a R9 270x VaporX LBRY@50 MH/s
can i put asus 280x and msi 280x together?