~ Zero
Domaining and any other type of discipline requires rules and guidelines. You can establish these on your own or you can borrow them from others.
My advice, after doing this for longer than I care to disclose, would be to NEVER EVER register or invest in domains that contain hyphens. This would be an okay domain at best WITHOUT the hyphen.
Quit wasting money on renewals and padding Bob Parsons fat wallet. Turn autorenew to 'off' and let this one sail into the wall on the third turn and go off into the sunset in style.
Good luck and may the force be with you!