The day, water, sun, moon, night -- I do not have to purchase these things with money.
— Plautus

Sell not virtue to purchase wealth.
English Proverbs purchases quote

Purchase not friends by gifts; when thou ceasest to give, such will cease to love.
— Thomas Fuller

If one man says to thee, Thou art a donkey, pay no heed. If two speak thus, purchase a saddle.
— The Talmud

Contentment is a pearl of great price, and whoever procures it at the expense of ten thousand desires makes a wise and a happy purchase.
— John Balguy