Get this, if the Avengers were really fighting in the real Manhattan, the destruction would cost them a whole lot of money. Tony Stark would probably be bankrupt. Disaster experts claim that the damage would set the city back more than Hurricane Katrina or last year's Japanese Tsunami.
According to Kinectic Analysis Corporation, a leading disaster cost prediction firm in the US, they did some modeling for The Hollywood Reporter and calculated that the physical damage alone would cost $60-70 billion, and would have economic and cleanup ramifications of some $90 billion, making the total cost of $160 billion.
By way of comparison, Hurricane Katrina cost $90 billion, and the tsunami in Japan last year $122 billion.
Damaged buildings will be expensive to repair, but the real damage is underground. If the damage were to be as real as the film, it could in theory cause significant damage to sub surface infrastructure such as gas, communications and electrical systems.