my strategy is this
1. you need the item on a one-off basis: for stores it's a daily affair. He's already relying on your desperation.
2. you have to know what something is worth (the cold hard $ value) before you negotiate - implies knowing how that product was made, material cost AND ALTERNATIVES.
3. YOU DON'T ASK for the price: you tell the store what you are willing to pay and why (the alternatives). Don't waste your offer-first-mover opportunity on asking him for his opinion - it'll usually be something ridiculous because he wants to protect his price margin info.
Example I need a 5 ohm speaker because my old driver broke:
1. did some research
Speaker Drivers and
winding my own coil So, convenience wise 2-2.5k (internet -shipping), but material cost wise no more than INR 500/. My alternative is to wind it myself and repair (cheapest INR 100 roughly) - do I have all the components/sources, yes except the Aluminium former.
2. The temptation would be to lie and gloss over your hurdles during negotiation but the store will know for sure everything about this business. Therefore:
3. Patience but here the store can waste your time/money depending. Why do you suppose they put up shop in SP Road? They can sit and you have to storm their muddy-moat/shabby citadel every attempt. (but for him it's home - he's already used to it and living in it) (which means finding a way to live economically in SP Road and discovering its sekrets - maybe)
Stores have numerous tricks to create the impression you are getting value! I WOULD NOT waste my time with them, negotiating/bargaining/checking with other shops - YOU ARE ALREADY paying for an overpriced item. Almost any import is x3-4-10 times the cost of manufacturing. Instead use the opportunity to learn more or do without! You won't win against a system that's rigged against you!
(note the cost of rice and ask yourself have you won?) My thread on this very same topic - documenting some of my experiences
You WON'T WIN in India against a competent storekeeper: you will leave thinking you did so. (Buyers are losers by definition)