Whats the RC cost of basic operations?

With HF20, Resource Credits were added in as the new bandwidth system. Whats the cost of RC to do basic tasks? I need to know for posting(I assume longer posts will cost more, so maybe initial cost + cost per byte), cost per comment(same as post), cost per vote(does it differ by vote %), transactions(including powering up/down), coustom_json(again I assume this varies by length, so initial cost + cost per byte) and claiming rewards.