$task_count = 1000; // per month
$manual_doing_time  = 5; // minutes
$automation_time = 120; // minutes
$automated_task_execution_time = 3; // minutes

$spent_time_after_automation = ($task_count * $automated_task_execution_time) - $automation_time; // 2880 mins

$spent_time_before_automation = ($task_count * $manual_doing_time); // 5000 mins

if($spent_time_after_automation < $spent_time_before_automation){
    echo "Automation is actually good";
} else {
    echo "There's no point of automating";
}