One of the differences between here and Korea, and I didn't find this out until the bill came, but they actually charge you extra for things like the coals, 6 Kuai (about 75 cents). It's not really a big deal, but why not just add the price in with the meat. I mean, who's going to order raw Chicken heart and not cook it?
Also, and I can't see this going over well with the Korean population - you have to buy kimchi for 8-10 kuai (over a dollar) and even the leaves are not free, another 10 kuai. My favorite extra charge was 2 kuai, for the dipping sauce which we dodn't order but came with the meal. We were shocked they didn't charge us when we asked for more garlic!