"Thus the average family is earning 280 dollars per month and lives normally off of that."
lol.... sure, as long as normally means lots of potatoes and cabbage, and a cramped soviet era apartment where three generations live in two rooms.
The apartments vary from place to place, but I can tell you this, you can take that cramped apartment in Moscow (everyone owns their apartments) and sell it to a Western corp for their employees for around $80-200K cash.
As for food, the diet there is more varied but the point is: no one starves and to buy a cottage (ducha) in the country side costs around $5K.
As for those apartments, many of those buildings are being torn down and larger, modern ones put up. The tenants of the old ones get a new modern apartment and the company gets a set of new open apartments to sell too.