Until a dedicated govn't organization is set up to supervise the domain investment in China. One thing is for sure: the big domain investors here would not let their domains devalue by not selling their domains unless the price is at least 18% higher than that from previous year, to offset inflation, capital hold, bank interests etc.
Types like pure digits or numbers have very transparent market price. But for Pinyin combinations, the price would vary differently a lot. As long as it's a Chinese premium(Chinese like it, not non-Chinese speakers think it's premium), it doesn't become cheaper. We heard people who lost money from investing in stock market or futures jump off the building, but none was about domaining. So, it sounds already pretty safe right?