should have a an online shopping cart & payment system out of box
I must disagree too, sorry. :-/ Afaik, Plone is a CMS, not an e-commerce solution.
Adminoptilude (Admin, Plone) commented
I don't think it would be appropriate to have e-commerce in the core, personally. Too far away from Plone's core feature set of web content management. There is an effort called GetPaid to produce a robust payment solution as an add-on though. This feels more appropriate.