Done lots of web designs for clients, but never been asked to do an online shopping site until now, and need to understand what's required.

I guess what I don't quite understand is what is the benefit of using something like zencart compared to just purchasing paypal pro? I think I read to that carts like zen cart can integrate with pay pal as well. Is it that I could install zencart on my own server and have better customization of the appearance of the cart? The client doesn't want the customer to leave their site, so I'm not going to go with basic paypal solution. Also, pricing will need to be in Canadian dollars - if that makes a difference in my options. I'm just not understanding if zencart is an all-in-one solution that allows to take payment, or do I still need to use something like paypal to integrate with zencart???

As this is just a start-up site, the client wants something cheap (like most clients always do). Is

The more I read and look at different shopping carts, the more confused I get.

im doing my research about online shopping and ecommerce so i read blogs about this but if you want it at firsthand information, you can refer to sitepoint