What would you offer for a horse like this?

Sadly, people don't buy potential anymore. In the US, he'd maybe go for $800-$1000 for someone with the money and time to school him. Being a light bucker and spooky is what knocks his price down a bit. If he were more level tempermented, He could go for closer to $1500. Not having papers might turn some people away, but I personally don't care if the horse is registered or not. The euro is worth more than the dollar so I would say he is over priced.