( saying ) to spoil sth good because you did not spend enough money or time on a small but essential part of it
SPOIL THE SHIP FOR A HA'P'ORTH / HA'PENNYWORTH OF TAR
Meaning of SPOIL THE SHIP FOR A HA'P'ORTH / HA'PENNYWORTH OF TAR in English
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005