To fix this issue Have you tried to put a break point into a stellar.js file code to see what options are passed there during initialization (actually, I got the same value I'd passed)? If you think, the problem with a scope, maybe you should try something like that:
$scope.selectedValue = function(value)
$scope.valueToSend = value + 1000;
factory.inputValue($scope.valueToSend); // this will set the new value in the factory.
console.log(factory.inputValue()) // this will get the value from the factory.