Which factor sets the ceiling on setting a product's price?

Customer's perceptions set the price ceiling - if they see the price as too high they won't buy it, demand will fall, and so will the equilibrium price. Their perception on the fairness of the price will affect how high the price can go before losing sales.

wheres the chart? so i can answer.

if it is for a job, then you should learn everything you can about the job, like what does it involve, what qualification is required and how you are the right person for that job. dress appropriately for the interview. get plenty of rest the night before. good luck!