Eron,
var users = {
"243919844": {
"name": "Александр",
"balance": 200,
"per": 0,
"sms": 16,
"wordd": 0,
"symm": 250,
"warn": 0,
"farm": 1,
"dbalance": 0,
"marry": 0,
"mstatus": 0,
"romance": 0
},
"273597295": {
"name": "Данил",
"balance": 4999995200,
"per": 0,
"sms": 42,
"wordd": 0,
"symm": 1140,
"warn": 0,
"farm": 1,
"dbalance": 0,
"marry": 0,
"mstatus": 273597295,
"romance": 0
},
"284643410": {
"name": "ГейНигерИзОткрытогоКосмо� �а",
"balance": 5750000000,
"per": 0,
"sms": 17,
"wordd": 0,
"symm": 184,
"warn": 0,
"farm": 1,
"dbalance": 0,
"marry": 0,
"mstatus": 0,
"romance": 0
},
"325287104": {
"name": "Никита",
"balance": 200,
"per": 0,
"sms": 1,
"wordd": 0,
"symm": 18,
"warn": 0,
"farm": 1,
"dbalance": 0,
"marry": 0,
"mstatus": 0,
"romance": 0
},
"331513444": {
"name": "Эльдар",
"balance": 200,
"per": 0,
"sms": 2,
"wordd": 0,
"symm": 41,
"warn": 0,
"farm": 1,
"dbalance": 0,
"marry": 0,
"mstatus": 0,
"romance": 0
},
"499562407": {
"name": "Марк",
"balance": 200,
"per": 0,
"sms": 0,
"wordd": 0,
"symm": 0,
"warn": 0,
"farm": 1,
"dbalance": 0,
"marry": 0,
"mstatus": 0,
"romance": 0
}
}
alert(Object.keys(users).reduce((a,b)=> a + users[b].balance, 0))