Just Say No

Users would input the dollar amount of a purchase they were considering and choose one of two options. Option 1) How much would this purchase end up costing at different interest rates (based on their own credit card rate) if paid off over a 1, 2, or 5 year time period. Option 2) How much would this purchase amount grow at 8% (or other return amount) over 10 years if they chose to invest the money instead of making this purchase. It would basically use pre-programed time value of money formulas with the user inputting the dollar amount and choosing among the different options.