Horse prices in Scotland are down the gutter too we had two of our colts at a sale and one of our colts (both yearling's at the time) went for the same price as a 16'2 broken piebald gelding who I gotta say was one hell of a looker.
I'm afraid to say that your be lucky to make over 1000 with her. But as you said if you set your price to something and say that the price is negotiable you may be able to come to a reasonable offer
Depends a lot on where you are located. Around here, $1000 would be a good asking price, $800 an acceptable negotiated price. Without show experience and proven hunter/jumper abilities, it's really tough to get much more for an OTTB.
Well, it really depends how quiet she is. Without seeing video of the quality of her movement, I would be say about $2000 if she is a very average mover (small steps, lots of knee). However, if she is a very good mover (floaty) I would ask up to $3500. I saw some OTTB's a while back, and the owners were asking about $2000 each and they were barely green-broke, but were exellent movers and very good prospects.