I think the ICE accessories are on the higher side. Check out other genuine accessories shops. Not sure whether GP road is the best place (I used to go there when I studied in Chennai - Dont know what's the trend now).
1) Floor mats will be cheaper. I got the full set for 1.5k in Cochin. Not the regular ones though. I got this from a carpet/home furnishing shop. It does a good job since normal car mats wont hold the dirt/mud.
2) You can try out other sun film brands which will be cheaper. I have Llumar which is cheaper.
3) Side Molding - Get body colored ones. I painted them since it didnt look good.
4) Bumper protection - I personally dont prefer this. Kinda spoils the look. No offense dude.
5) Door visor - No (again, a personal recommendation)
6) Spoiler - Expensive, if you are talking about the OEM
I would say get bumper molds, Under body coating and central locking assembly from MASS and all others from a genuine accessories shop outside. Hope others can direct you to the right shop in Chennai.