You'll need to choose. You won't be able to say "I'll take 2 at Price A, but at Price B, I can only take 1." If 2 tickets at $320 each is too much, but 2 tickets @ $240 is not too much, you could:
* Request 1-2 tickets in the $240 tier only (10,000 tickets)
* Request 1 ticket in the $320 tier (15,000 tickets), which would still allow the possibility of paying only $240 for one of the 10,000 cheapest, and increase your chances of getting a ticket.
During the registration process you will need to select the highest price you are willing to pay for tickets. You may be awarded tickets at that price or at a lower tier.