You are guestimating that 4000 gold phones were sold in the stores based on a 10 per store rumored number you've heard and 400 stores. Then you guess that retail is only 10% (another guess) and so multiply you original guestimate by 10 to get 40000 gold phones.

It's quite hopeless guesswork. We don't know the distribution of models in retail or online. We don't know how much is sold online compared to retail. We don't know how much was sold outside Apple's retail stores (by e.g. AT&T). We don't even know the geographical distribution (i.e. higher gold-ratio in China than US).

If we assume a factor 3 to 1 sales of iPhone 5S vs 5C based on Localitics'report (1), Apple has sold between 6-7 million iPhone 5S. Your 40.000 number isn't even 1% of that, so I think you are an order of magnitude off still.

[1] http://appleinsider.com/articles/13/09/23/iphone-5s-3-times-...