When you buy from Alibaba, a lot of the shippers don't want to use trade assurance or escrow. Do you trust them?
Like Amazon they are one of the trust e-commerce store to buy the any products. In top 10 list of the world they are also in the list. I know you buy the components for GPU rig and they sells antminer series hardwares.
If there is no source in-between you means you can always go with the escrow that is the right.
Alibaba have the selling rights and guarantee for the purchase.