Do shareholders know something that I don't know when it comes to CMG? Is this a stock that is really worth 34 times its upcoming fiscal year's earnings (ending Dec. 31, 2013)? I don't think so! Who in their right mind would pay that for a fast-food restaurant when Apple ( AAPL) is selling for a little over 11 times forward earnings (fiscal year ending September 24, 2013)? Not even Panera Bread ( PNRA) is so richly valued. Here's the five-year chart with its price and PSR. PNRA Price / Sales Ratio data by YCharts Yes I've heard the theory that same-store-sales growth is what justifies the CMG share price and nosebleed high P/E ratios. I'm not buying that reasoning. Like other overpriced, unreasonably highfliers -- remember First Solar ( FSLR), which in the past 52-weeks traded at $127? -- it wouldn't surprise me if one of these days CMG comes down to earth and sells closer to $200 a share. What might trigger such a fall? How about a negative surprise like lowering its earnings guidance or missing its next quarterly earnings projections? I'm not saying it will happen, but caveat emptor! At the time of the publication, the author was long GG. This article is commentary by an independent contributor, separate from TheStreet's regular news coverage.