7.5 million yen for an upgrade packet sounds exceedingly expensive. It would obviously suggest the basic model is more than that, like 10 million yen. That would already buy you a sports car. Few people have sports cars, and thus even fewer would have domestic robots costing that much. It seems to me that after the very first novelty phase of the technology, something like 30,000 dollars should be the maximum for the basic models (though with options I imagine you could double the price). It's still expensive, but those who really would want one would be able to fork out the money. Eventually there should be models costing only $10k. If you look at Mina, she's very basic, without an imitation skin or anything, apart from the face. The mouth isn't even animated. The production costs can't be that high.
I'm not an economics major, but the price seems far too high for those things to be common at all. Seeing how some random salaryman got one, even if secondhand, they can't be that scarce. He's not also driving a Porsche, is he?