Buying from China has it's pros and cons. Shipping can take weeks, most Chinese sites won't ship or take orders during their holidays, which can mean days. You might also pay higher shipping fees, so if you only get a few items you really won't be saving anything and waiting longer for it.
Chinese sites do offer things at a lower cost since most items are manufactured there. Juice choices are limited and yes, they can be sold of items and juice.
I don't buy from China because I prefer buying from companies here in the US. The shipping is cheaper and quicker and there's more variety. Just my .25cents, adjusted for inflation.