(1) If costs are incurred improperly or without reasonable cause or are wasted by undue delay or negligence or by any other misconduct or default or from any other cause the amount of costs is excessive—
(a) only costs that were reasonable and proper must be allowed; and
(b) a registrar may assess those costs at a gross sum.
(2) A registrar may apportion costs assessed under paragraph (1) among different parties.