Well we have understood the business problem and approach to solve it so now lets implement in a GUI way with the help of shiny.
Shiny is a great platform in R to make neat dashboards and with the introduction of shiny dashboard things are even neater.
While coming to the modelling end due to the constraint of speed I have used only a simple linear regression and am plotting output of linear regression, but if we were to make this a business application we could implement all the models using the framework of this code.
If a real user was to use it he may have to wait more than hour to see his result but the value and simplicity it derives for a user is tremendous.
I have uploaded the code on git which you can view here