Ibn Abi al-Zinad narrates from his father Abu al-Zinad (may Allah have mercy on him) that the jurists of the people of Madinah used to say: When two men make a sale and disagree about the price, both of them will be asked to take an oath. Whichever of the two refrains, the judgement will go against him. If both take the oath, the word of the seller is accepted and the buyer is given the option: if he wishes, he takes it at that price, otherwise he returns it.
(b) It is narrated from Qadi Shurayh (may Allah have mercy on him) that he said: If both of them refrain from the oath, the sale will be cancelled.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10814