Shipping and warehousing only accounts for a tiny fraction of the cost of most consumer products. It's hardly an order of magnitude difference.

Chinese consumers can buy pretty much the same products as Americans (with a few limited exceptions such as weapons and narcotics). But they tend to save more on a percentage basis. Some of this is cultural. But mostly it's a practical reaction to a lack of a social safety net. Even though China is nominally communist, as a practical matter most consumers have to pay out of pocket for healthcare and retirement hence they save for those things. They also save to purchase residential real estate since it is seen as the only safe store of value and owning a home is somewhat necessary for marriage (at least for men).