This is a personal preference questions… if he is familiar with WordPress then you can definitely build it on WordPress using WooCommerce or one of the other e-commerce plugins that’s available.
I would say it also depends on two other things:
1) Is the site only going to be storefront or does the person plan to provide other content using a blog area? WordPress is by far the best platform for the blog so if he plans to have a blog area it might be best to use WooCommerce for the store.
2) What is his budget for hosting? If he wants to keep costs down then WordPress/WooCommerce will be best because many of the other widely used shopping cart systems out there such as shopify are bundled solutions which include hosting and software and therefore are more expensive than most WordPress hosts.
Hope this helps.
D
(@semtak)
I guess he asks if WordPress is able to handle so many products and will not work slowly. I have a customer who has 500 products and the store works ok but is on VPS.
