Imagine an online business that sells custom shirts such as "CustomInk.com". They have a pricing formula that might look something like this: $11.95 per shirt for the "Hanes Authentic Crewneck Short Sleeve T-Shirt". If you order 25 or more shirts, they might take 10% off of your entire order, and if you order 50 or more shirts, they might take 20% off of your entire order.

Given the number of shirts you would like to buy, return the amount of dollars that it would cost for that order as a decimal number using the formula above.