Payment of the price by the buyer is an important ingredient of a contract of sale. If the parties totally ignore the question of price while making the contract, it would not become an uncertain and invalid agreement. It will rather be a valid contract and the buyer shall pay a reasonable price. (Section 9 of the Sale of Goods Act, 1930)

In the give case, X and Y have entered into a contract for sale of car but they did not fix the price of the car. X refused to sell the car to Y on this ground. Y can legally demand the car from X and X can recover a reasonable price of the car from Y.

As per the provisions of Section 2(10) of the Sale of Goods Act, 1930, price is the consideration for sale of goods and therefore is a requirement to make a contract of sale. Section 2(10) is to be read with Section 9 of the Sale of Goods Act, 1930.

According to Section 9 of the Sale of Goods Act, 1930, the price in a contract of sale may be fixed by the contract or may be left to be fixed in manner thereby agreed or may be determined by the course of dealing between the parties.

Even though both the parties missed to discuss the price of the car while making the contract, it will be a valid contract, rather than being uncertain and void; the buyer shall pay a reasonable price in this situation.