In the nearly twenty years of going to races at Martinsville, there has always been someone selling tickets. Try findiong someone with just one ticket to sell to avoid the scalper since a one ticket sale means you most likely get to sit next to the ticket seller and the ticket was one left over from a buddy who couldn't make it at the last minute.
Should be no problem at Martinsville and there are hardly no bad seats there, most offering better views of the track. Even the backstretch is a good seat and of course the higher the better but still, few bad seats no matter where they are located. The turns are the good since it isn't far between the first and fourth turn and you can still see all the action.