I heard that to get another chance at Hashirama or Tendo instead of 400 seals it will be 600 seals for a total of 1000 draws and that you can still have the chance of drawing a duplicate.
But I could be wrong, maybe is just another 400 seals and you get the one you don't have. ( Let's hope this is the case ) :)
I got Tendo and I wanted Hashirama >