Alibaba is like Ebay or Amazon but on the international level. You have manufactures that sell their products on there and most are very familiar with the process of import/export into the USA. A majority of the suppliers are Chinese. I'm not familiar with any of the suppliers that are listed for the utility markers, but there are some multi-year gold rated members.
Purchasing through Alibaba offers a level of protection in the event that the supplier doesn't follow through with the order. Most of these companies make their whole living off Alibaba and if there is an issue Alibaba will shut them down until the issue is resolved. I've not had any issues. I've had customers that have had issues and as soon as they said they would file a complaint, they kicked it into gear.
We've also discovered that unless you buy in quantities based on container sizes the pricing is going to be similar to what you can get in the states.