Mals E-Commerce--ever heard of it? Well it's like a online shopping cart sort of thing. It's where you place a shop at your site and people can simply buy an item buy clicking 'Place in cart' or something like that. I've seen a few sites with this shop, it seems okay. I wanted something like this for my site too but too bad I don't own a credit card. :/

http://www.mals-e.com/

Have you looked at some of the shopping cart scripts in fantastico in your cpanel? I think some are paypal-based.

Failing that base your site on php-nuke & install aser-shop, that is definately paypal based, & is pretty good too.

I have never used mals, i have used zencart which is a similar program but right now im using oscommerce (www.oscommerce.com) it is very good and is much better than zencart (in my opinion), also oscommerce can be installed through fantastico. It can be modified with many different moduals so it works how you like; some can be quite hard to install though. Hope this helps.