Looking for Mon Cheri 17974..please help!!

Hi Girls!
Just wondering if by any fat chance anyone knows where I can get a Mon Cheri dress style 17974 for a good price...my mom found it and it's the perfect dress for her but it's $650!!!! If anyone know where I can get one or if anyone is selling one, let me know...thanks girls!!

thats the designer my grandma got and the dress was expensive...i even looked online and couldnt find it cheaper