Food sample is a business tool. So we may think it's difficult to obtain it. But it isn't true.
If you live in an urban area, you can find some companies that making food sample in a telephone directory.
In Osaka(I live in), there is a shopping street that is called "Doguya-suji", and we can purchase food sample in there. I have seen some people purchase the sample of octopus dumpling as souvenir.
In the case of inexpensive sample, the price is about 500 yen. The other side, in expensive sample, the price is more than 30,000 yen.