3-2-1 Buydown vs. price reduction calculator

[Benjamin Giles]

Does anyone have, or is anyone aware of a calculator with inputs to show me whether a seller paid 3-2-1 rate buy down vs price reduction is best, where I have ability to input for how many years. 

I have seen very basic versions that only show the lifetime savings after 30 years but I want to be able to input variables for rate, points, number of years, and price reduction.