This is a 1989 Edwin M. Knowles Collector Plate titled "I Could Have Danced All Night" from the My Fair Lady 25th-anniversary series featuring artwork by William Chambers. 

Plate Details

• Manufacturer: Edwin M. Knowles China Company

• Artist: William Chambers

• Series: My Fair Lady 25th Anniversary Collection (Second Issue)

• Bradex Number: 84-K41-75.2

• Plate Number: 6400A

The current market value for this plate complete with its original box and Certificate of Authenticity (COA) is $10 to $25.

Value Breakdown

• Plate Alone: Loose plates without documentation typically sell on the lower end, around $5 to $12.

• With Box and COA: Having the original packaging and the matching paper certificate brings the value up to the $15 to $25 range. 

Like most mass-produced collector plates from the 1980s, the original "issue price" (which was $24.90 back in 1989) has not appreciated significantly due to high supply on the secondary market