thank you guys for this PERFECT steps but my budget is not so big right now so if i correctly understand if i bought this R9 280x graphic card(only ONE!!) it will be good to main crypto-coin?? if i correctly calculate on this page..

http://www.coinwarz.com/cryptocurrency/?sha256HashRate=1000.00&sha256Power=500.00&sha256PowerCost=0.1000&scryptHashRate=750&scryptPower=300&scryptPowerCost=0.1000&sha256Check=false&scryptCheck=true

for example i buy this R9 280x graphic card if i must change something in my hardware??(remember only one!!) and please be look at my current hardware set-up