php/mysql for storing items, prices and totals

i have a form database which holds people contact details and credit card information. my client now wants the database to contain the items they have ordered together with the item number and the price of the item. also the database needs to calculate how much the total order is and to list the total order that the person wants. its for a jewellery store so the extra info to be included in each row is:

item(s)
item number(s)
price of item(s)
total price.

the site is heavily ladened with javascript. i want to move away from this for obvious reasons. i know how to transport data from one form to another but what i want to do is to have a the user tick what he/she wants and have a runing total of that. at the conclusion i want a submit button at the base of that running total to transport the data over to the main form which will contain all the items and prices they have ticked with a total. this info that is in the form will then be transported to the database. so the calculations should just be php based but the total or items and the total of cost should be stored in the database

You should probably just download an ecomm package that already handles all of this while also addressing security concerns. (It's a horrible idea to store credit card numbers, for example.)