I like the definition of a cynic as someone who knows the price of everything but the value of nothing.

Sorry Bill. That's an accountant not a cynic.

Sorry, CK. Bill has it right. Oscar Wilde, Lady Windermere's Fan, Act 3:

Lord Darlington. What cynics you fellows are!
Cecil Graham. What is a cynic? [Sitting on the back of the sofa.]
Lord Darlington. A man who knows the price of everything and the value of nothing.
Cecil Graham. And a sentimentalist, my dear Darlington, is a man who sees an absurd value in everything, and doesn't know the market price of any single thing.