Custom work program

[pom007]

First up, I have absolutely no idea about programming! so be gentle.
Just wondering if anyone can advise the best code to create a custom quote calculation program for my work?
We work on a lot of square metre rates, various quantities etc etc. So it would need different price ranges, qty discounts, suppliers etc etc.
Hope this makes sense?
Thank you.

[Matthewfleft]

Also what from this follows?