Indian - in the broad sense - postmarks can command premium prices. However they're vastly more diverse and specialised than anything in Australia, and the literature is also vast and specialised. As in Australia, though, and most of the rest of the philatelic world for that matter, they remain a minority taste. Prices tend to reflect that, with world-class rarities (one or two known) selling for three-figure sums.
For instance, this postcard is the only piece of commercial (non-government) mail I've ever seen from Pati village in Barwani, in India. A very average strike of the Pati CDS, too. On a good day, it might sell for $150, against maybe $50 for a similar card from a common post office.

Postmarks remain the preserve of the sophisticated collector, so you're not likely to find the sort of crazed price inflation we see in, say, mint unhinged modern Chinese stamps.