Not enough answers to be representative, but here is what we have so far:

     % Customers who find the price acceptable
       ^
       |
  100% |------|
       |      |------|
   80% |             |
       |             |------|
   60% |                    |
       |                    |
   40% |                    |
       |                    |-------------|
   20% |                                  |
       |                                  |
       -------|------|------|------|------|-->

       0$     5$     8$    10$    12$    20$

                  Price per month

UPDATE: Upvoting another person's answer is something that I cannot differentiate, so I cannot include it in the summary above.