I understood the site was bought as a long term investment by the current owner and when the right offer come in he would cash in on his investment, In the mean time the site was least for go kart racing. I very much doubt any Speedway promotion could afford to buy the site or offer a substantially better offer on a lease than the go karts, so i suspect is why it was discounted when speedway was removed from plough lane.
If Paschal Taggart is serious about building a new stadium then this could be a much cheaper option should he not obtain plough lane. Transport links are good with tram and train station close. The site is mainly surrounded by common land and the old sewage works with an industrial area between the site and the closest housing and I am sure some noise reduction measures could be designed into a stadium.