Build an Online Store

I am looking for the most simplest of all. A quick job. I need a shopping cart which is able to sell multiple products and process the sale out to mastercard, visa, paypal etc. I want to be able to upload the products on my own. I work with Joomla and Webplus x7/x8 so if possible - maybe this is an advantage. I have a very small budget. This is a trial for me so am testing the waters hence have a very small budget. Get in touch if you are willing to work with me.