Lip honour costs little, yet may bring in much

Similar English and Irish sayings:

Politeness costs little (nothing), but yields much Politeness costs little (nothing), but yields much
Good words are worth much and cost little Good words are worth much and cost little
A child’s service is little, yet he is no little fool that despises it A child’s service is little, yet he is no little fool that despises it

Proverbs and English sayings