Right now I can spend $6750 for 1000 DRK to setup a masternode. Earnings per day would be: 1.019 DRK = $6.912
I can also spend $6750 for 5870 XC. Earnings per day from POS would be: 0.54 XC = $0.616
Yes but you are forgetting about the fact that you will also get money from it being a node.