Article 1591 of the Civil Code
The price of the sale must be determined and designated by the parties.
Cass. 3rd civ. July 18, 2001
the price is determinable if it is established on the basis of significant official quotations of the determined market Cass.civ. 1 December 14, 2004
In the event of partial non-fulfillment of the obligation to deliver, there is no action for price reduction, but only for damages Cass. civ. 3 January 29, 2003
In the absence of a conventional fixing of the price and in the event of disagreement between the parties, the judge cannot fix the price at the market price because by determining in this way, by elements external to the agreement of the parties, the judge would proceed to a judicial fixing of the price Cass.civ. January 1, 19 1999
Likewise, the judge cannot rely on the estimate of the legal expert to determine the price, if the parties have not fixed in advance any objective element allowing the price to be determined. Cass. civ. 1, July 16, 1998 , Cass. civ. 1, 24 February 1998
Price fixing by a third party
It may however be left to the arbitration of a third party; if the third party is unwilling or unable to make the estimate, there is no point of sale.
Transfer of shares and determination of the price
Court of Cassation, Commercial Chamber, October 06, 1998,
Sale and vileness of the price
In the event of a low price, an action to cancel the sale can be exercised Cass. civ. July 3, 18, 2001