In the same survey, the research group also got confirmation from Apple supply chain partners that Apple is indeed working on a cheaper budget product.
There are also rumours that the next iPad mini 2 will be equipped with Retina display. There is no doubt that this will increase the manufacturing cost of the product. However, it seems that Apple is still able to keep the SRP of the product to be at 329USD. If what CitiGroup has predicted is true, we will not only see a new budget iPhone for the market, but also a budget iPad mini.