As with everything these days, purchasing a new mattress will overwhelm you with choice. A large number of brands, too many models and each manufacturer has their own "unique" feature that as one salesman put it "fabric takes germs and kills it in the air".
I discovered the following
1. The staple coir, which is essentially a layer of foam on both sides of coir is banished to the lower end. Spring mattresses are where all the action is. Most display pieces are spring.
2. You have a number of brands, the old Kurlon, Sleep well etc with international brands like Peps, Restonic, SpringAir
3. There are two types of spring mattresses, Bonnelle, which is interlinked Springs held by a frame that runs through the length and pocketed Springs that are each in their own chamber.
4. Pocketed are better or at least they are more expensive, hence better.
5. They have normal to, pillow top with a thin layer of foam and Euro top with a thick layer of foam. Why Euro top, I don't know
6. You get various thicknesses, 6,8,10"
For a queen bed, the range stays at around 15K for Bonnelle but can quickly go to 30K depending on thickness, top etc. The dealers will give 15-20% of mrp. If you're good at bargaining, even more.
FWIW, we ended going with Peps. Maybe, it was the non stop advertising on RadioOne that did it for us.