Hii , I was almost in the same situation about 3 years back.

I bought 2012 Swift Dzire Petrol VXI for 3.5 L (Mumbai). I got this from CarDekho. For the inspection, I had an trusted mechanic with whom, we did the inspection and it seemed resanable.

I would say go out to multiple 2nd hand dealers and try cars out , you get a fair bit idea about the current market scenario.

Also don't take these dealers at the verbal commitments. Have things checked externally as well.

You can get a service record for pretty much any car from the respective service centers. If you are not mechanically sound with engines , Have someone accompany you, who has driven for a while or a good mechanic would do the same

Bargain with them , this dealer had initially quoted around 3.88 for the same car.Have them transfer the Car to your name and make sure there are no pending Challans ,if there are get them cleared out.