Database Design - Ratebooks

We are undertaking a project where we utilise a quotation system for Contract Hire, Hire Purchase etc.

In the past we have constructed 'ratebooks' or a table that pre calculates all possible results, ready to be called. Based on a number of variables but including Term of Contract & Mileage driven.

We present the visitor with a list of items and the appropriate Monthly figure. This is very quick but it relies on the pre-built info.

We are looking for possible alteratives for a more flexible approach.

Any ideas?

I don't understand how this is a problem. Any modern DBMS can do on-the-fly calculations in a query. So, if you have a formula that you use to populate your static lookup table, just translate that into the SQL query. The output can look identical to the end user, (make the Rates table a VIEW, instead of a static table). Now you don't have to update your Rates table every time you change a parameter.

On a side note, what's the poll for?