Well, Chennai's prices are always hot, especially in the city and now everywhere even beyond the city limits. Bangalore is another story and prices now are heating up unlike 5 years ago. With more room for construction around Bangalore International airport and in Ecity, Prices are still better than Chennai. I am not knowledgeable to comment on other metro. But now, in the US, SFO Bay area tops the list of increasing prices for even junk properties. Over priced NO.. because available land is limited in the city (Chennai especially) and so the demand and so the compounding effect on price, with too many rich politicians paying cash (black money) to grab the available properties in the city locations.
I feel realty prices in india is over priced in metros. It is because of scarcity of availability of land in metros and next thing is politician-builder nexus