Shopping cart integrated with PayPal

I need to have a shopping cart created that integrates with PayPal. It is an editing website. The person enters a word count, and the price is generated below. The customer decides whether they want to add this item to the shopping cart. If they do, they click on the "Add to shopping cart" button and they then are taken to the shopping cart page, where the item has been added to the shopping cart. Then they fill out information about themselves such as their email address and upload the document that needs to be uploaded and they fill out other information such as credit card information and then they click on submit to pay. If everything goes well then the payment goes to my PayPal account, and at the same time I get the paper sent to my email and I can start editing. When the paper is uploaded it needs to go to my email. There is also a minimum payment the customer has to pay so this needs to be built in so that the price that is added to the shopping cart is never lower than this minimum payment figure. I also need to be able to customize the minimum price and the prices in general if I change my mind about them later. I have a simple price generator (Instant quote script) so I don't really need to have that coded. I also need to generate copies of the shopping cart page and script for other services so it should be easy to duplicate. I will have an Academic Service, a Medical Service and a Business service and a fourth one and maybe a fifth and sixth one. I suppose you can make just one for the Academic service and then show me how to duplicate and customize for the other services if needed. It should be able to be used on a Joomla or an html site. I only want Javascript, CSS script. I don't want to have J-Query if it can be avoided. You have to help me with all stages right up to the point where I receive payment, a receipt is sent automatically to the customer (I suppose via PayPal) and you have to help me with the PayPal side of things too. All the different pages must integrate. I will only release money for a completed job that works. It will be tested from beginning to end and if it doesn't work at any step, then no payment will be given. I need someone experienced with this so only people who have experience in making shopping carts need apply for the job. The job needs to be completed within 24 hours of money being put into escrow or else the project will be canceled citing the passed deadline. Please abide by the conditions set out in the job to avoid difficulties later. If you show me the work you have done within the 24 hours and it doesn't work, I will let you have another try if it is before the deadline. If the work fails a second time for whatever reason, then I will have to cancel with you. These are my conditions of project. See the attachment.