If you don’t care if you get the land or not, double the discount or triple it to be unreasonable. Chances are nobody will take you seriously, but maybe you’ll get a fish or two. You don’t know what are the reasons for sale, maybe somebody is desperate to get rid of parcel for any price quickly, maybe somebody fell behind with repayments and actually bank is forcing the sale as with houses and banks don’t care. All they want is to get their money back. Cruel to sellers, but you never know if you don’t try.