Welcome to Pinside.
I think a good cleaning would go a long way to help your ad. Pretty sure under all that dirt is a nice looking playfield! Good news it actually protects it and is easy to clean off.
I'd also review the market archive to see some recent past sales of this title, or consider changing your price to OBO.
Here's a split screen thingie I made (while I impatiently wait for the Maiden LE reveal) with yours and a recently sold one... if you're looking to get home use only pricing price you'll have better luck if you make it shiny 
GLWS!
