Like your salaries, you can use kSPN to express much more big "money" of SpartanCoin Currency. one kSPN is one thousand SPN.
If you want to buy three cups of water for 500000 SPN, you can say that you want to pay 1500000 SPN. In this case 1500 kSPN is more convenient than 1500000 SPN.
1kSPN = 1000SPN
1000kSPN = 1MSPN
1,000,000kSPN = 1GSPN