To be honest, most rubbles that are on vendors at the moment have been on vendors for a very long time, mainly because they're overpriced, or (for the very low end) because there's no demand.
If you'd like, I can take a look and try to give you some estimates; Leonidas frequently is willing to do so as well. Alternately, if you want to post some screenshots, we can try to help out here on the forums.