Don't spoil the ship for a ha'pworth of tar
If someone spoils the ship for a ha'pworth (halfpenny's worth) of tar, they spoil something completely by trying to make a small economy
spoil دو تا معني داره 1-تباه كردن 2- تاراج كردن
tar هم دو تا معني داره 1-قير 2-ملوان
تاراج نكن كشتي را به خاطر يك ملوان بي ارزش (نيم پني )