HuRun, which calculates an alternative luxury price index for a basket of 62 high-end goods and services (32 of which are imported), said that while its index was down 2.79 percent from 2011, it was still 2.74 percent higher than China's national consumer price index.

And over the past six years, HuRun's luxury price index has outpaced the national consumer price index by 38 percent.

Of the nine categories measured by HuRun, luxury travel prices increased the most in 2012, up 11.92 percent from the previous year. Only one category, jets and yachts, grew slower than the national CPI. Luxury property was the only sector to see a drop in prices, but they have still doubled over a four-year period.

Two factors have played a significant role in the price increases—depreciated currency exchange rates and changes to import duties, HuRun said.

 China's millionaire population continues to boom and seems largely unaffected by the luxury price increases. There are now 271 billionaires (in U.S. dollars) across mainland China, up from 189 the previous year. And there are 1.02 millionaires, an increase of 6.3 percent over the previous year.