^^
That is because most of these sellers are importing action figures and collectibles at a huge cost. It is only natural that the inflated price will be passed on to the end buyer. Moreover, all those people are paying hefty sums to put up a stall, they will obviously want to recover their money.
I saw some collectibles for decent prices, but then I am an avid collector. Egg Attack Iron Man Mark 42 for just 6k, which is competitive even on the international market. DC Collectibles Blue Line Batman White figure for 3k, cheapest I have seen one go in the US is $38. DMK-03 TF4 Optimus Prime kit for 9k, whereas the retail was $120. If those aren't top value deals to be found in India without the hassles of importing, paying huge customs duties, exorbitant conversion rates, then I don't know what Indians really want.
What really helps is knowing what exactly you want, what price it goes for in the international market, and reasonable markup that Indian sellers will charge. If, OTOH, you go there like a wide eyed kid gawking at the merchandise then you will find everything overpriced and come away with a bad impression.