There is no more expensive thing than a free gift.

Montaigne
Profession: Philosopher
Nationality: French

Some suggestions for you :
No-one is exempt from speaking nonsense – the only misfortune is to do it solemnly.
It is the mind that maketh good or ill, That maketh wretch or happy, rich or poor.
Confidence in others' honesty is no light testimony of one's own integrity.
I will follow the right side even to the fire but excluding the fire if I can.