kristalsoldier,
There are several pros and cons of buying a new car vs used car. I suggest you go through the detailed article written by GTO on this topic.
In short, the biggest advantage of buying a used car is that you get a bigger and better car for the same money.
The disadvantage is that you do not know the past history of the vehicle. You can never be sure that the previous owner has maintained it properly. The vehicle may look good on the outside, but unless you are well versed with cars, you won't be able to make out the condition of the internal components of the car in a short test-drive.
Since you are a novice at buying cars, there is a good chance that the salesmen at used car dealerships would take you for a ride (pun intended).
Also, used car may save you money in the beginning, but it will require you to shell out more money towards fuel and maintenance bills, as compared to a brand new car. A bigger (used) car will generally have less fuel efficiency and more costly spares/service as compared to the smaller (new) car which you can purchase with the same money.
On the other hand, a new car comes with 2 year warranty and peace of mind. You could also opt for extended warranty for a new car. A new car goes through proper quality checks and you are (generally) assured of a good quality product. (New car can also have a manufacturing defect, but the chances are very less)
Personally, I would not spend 4-5 lakhs of my hard earned money on a used car. This is just my personal opinion, all people don't think this way.
My suggestion to you would be not to go for a used car unless you know the owner and are aware of the past history of the car or you are so well versed with cars that you can make out the condition of a used car by seeing/driving it.
I would again stress that you should consider taking a car loan. You don't necessarily have a take a loan of the full amount. You can make partial downpayment and take a loan of the balance amount. For example, you could make a downpayment of 4 lakhs and take a loan of 1 lakh. Taking a partial car loan would help you to increase your budget marginally so that you don't have to make a compromise on choosing the model or variant. You could also purchase the accessories with the balance amount.
Regarding my recommendations, Santro and Getz are aging models. Hence it makes more sense to go for these if only you are considering used cars. Maruti cars are generally overpriced in the used car market, hence I have not suggested any.
If you decide to buy a new car, I would suggest that you choose from models which are fresh in the market - Ritz, i10, Estilo and Beat are some of the newest models in this price range. Again, I have suggested i10 1.1 only, since I consider Ritz to be more value for money than i10 1.2.
Swift has not been suggested by anyone since Swift is due for an engine change. In the used car market, Swift is not that readily available. And if at all it is available, it is generally overpriced.
Also, in my opinion, Swift is not easy to drive and park in Bangalore's chaotic traffic.
Rohan,
Bangalore