If you don't have anything eles, I leave now./If you don't have more topic, then I leave./ then I say goodbye./ If there is nothing eles/more, I will leave.
If you need any help, contact me at any time.
If you are in diffculty and need help, you can call him. He is a trustworthy friend.
The price in this shop is cheaper than the other one. Let's shop here in future.