The thing it has going for it as a positive is the larger seat size, since that seems to be needed by many and is harder to find.
I have to agree that you should do some research on what they are selling for. You might also look around at how other ads are worded. Telling the specs of the saddle (like the wording of the ad Dover had for it) is more important than telling someone who is shopping that this saddle is popular in the hunter and jumper ring.
I would also get more photos, and better quality ones without the clutter in the background. Look at other saddle ads; they include photos of the billets, of the nail and nameplate, stirrup bars and usually a complete shot of the underside.
The two photos posted don't show enough detail for me to be willing to risk an online purchase.
My boyfriend just bought one of those brand new from dover for $450. It is an 18" and was supposed to be "slightly blemished" but we couldn't find anything wrong with it- it looks brand spanking new. I think you might want to lower your price as Circuits are not in high demand (like kitten_val said) and that saddle does look pretty used