Penny Black Valuation

Hi All,

Since I am still relatively new to stamp collecting, I would appreciate your help with determining the valuation of a Penny Black I have.

I sent the stamp off for expertizing and plating. The final opinion rendered by the expertizers was - "Great Britain, Scott 1, plate 10, used with black Maltese Cross cancel, genuine, corner creased upper left, frame damage lower left corner."

So, based on the corner crease and frame damage mentioned, what percent decrease in CV in catalog value can I expect for this stamp?

Stamp image attached.

around a 100$ ?