First with a piece of Lalique I check to see if the piece in question was actually produced by Lalique-- this piece in your photo was it is called Leda & the Swan approx. 1960 next you will need to become familiar with how Lalique signed pieces. Handle the piece see if quality is perfect and has some weight. At auction in this market I would not pay more than $200.00 for an original Lalique Leda & the Swan. As far as John Moore from Ipswich they can run from $300.00 to into the thousands.