Craigslist ad says "$480 cash. Price is firm." Buyer: "Will you take $420 for it?" Me: "No, I discounted it a lot already because of condition." Buyer: "How about $450?" Me: "I'm afraid not. The price is firm and there are others waiting to see it if you don't want it." Buyer: "How about a discount since it doesn't have a case?" Me: "Sorry, the price is firm." Buyer: "But I'll need to buy a case."