http://www.moderncoinmart.com/cart1/product.php?productid=23677&cat=202&page=1 Current sell price at Modern Coin Mart is $229USD (1990 China 1 oz Silver Panda 10 Yuan Small Date NGC MS68 Mint State 68)
Yes. But i think the dealers with the ngc coins use the cost thing not the rebuy thing to put the sell price. If they buy at 190 they sell at 229. They can rebuy it at 100 but the sell price is based in buy price. In the bullion dealers they use the rebuy cost to sell.
If I'm not wrong, SD is more rare than the LD. So for my case, guess got to hold for the next 3-5 years. And don't know can break even or not.