OK, so we've reached the point where, in a modern and global market, consumers and businesses are heavily driven by price. That's good, you're making progress. We can also see from the same evidence, that often they are willing to purchase from further away in order to ensure those low prices.
So the next stage is to ask yourself (or allow me to) what is it that enables China to sell to the world that, say, Germany cannot replicate. You've touched on one already - the cost of employment. That would be an excellent start to leaving the EU - costs of employment have risen significantly in the EU. Another unique factor in Chinese success is low regulation on businesses - something impossible from inside the EU. After leaving, we will be in the perfect position to reduce the cost of regulation and to allow businesses to sell at competitive prices around the globe. Thirdly, by trading at (and often below) WTO tariff levels, we will be able to sell goods without any external influence increasing prices. Yet another way of undercutting the competition and increasing UK exports.
So we've established that we can compete with, and take business from, those within the EU with a more expensive cost model. That's good, now let's lead on to other drivers of purchasing decisions.
I like wine but I don't consider my tastes to be particularly experimental. The vast majority of my wine comes from France, and most of that is from Bordeaux or Burgundy. If I lived in the US, Japan, or anywhere else, my wine would still come from France. Most of my clothes come from Italy, France or the UK. Again, no matter where I lived, I would be buying those same clothes from the same places. I'll also add that I've heard some fairly solid rumours that some of these designers are having clothes made in Eastern Europe and the Far East. I assume you don't need me to explain why they would do that. My car is from Italy - that wouldn't change. I wouldn't drive a Japanese car if I lived there and I sure as fudge wouldn't drive an American car no matter where I lived.
So millions of people in both their personal capacity and the corporate world choose to buy from places because they're the cheapest and they choose to buy from places because they're the best. Unless you're proposing some kind of permanent block on all trading with the EU, people wanting to buy from places near to them will still be able to do so.