did you ever bribe a traffic cop?

No, I have never in my life paid a bribe to anybody and I don't think I will in future either.
Having said that, I DO understand that bribing your way out of any difficulty is far easier and makes a lot more sense to a busy person, who doesn't want to waste precious time in a Court of Law, where the Judge himself might be corrupt, to start with!

Usually, traffic cops in India as for around Rs. 500 for a minor offence, but settle for around Rs. 100 to Rs. 200.
If you are lucky, you can get away by paying much less, and giving a big smile along with it!

In my country, it cost around 500 ruppes(10$)...

I've been tempted to, but my concience got the better of me. The last time I got caught was for driving past a red light. I tried explaining to the cop that I could not see the light at the crossing because of this huge bus going so slowly in front of me and by the time i got to see it I had already crossed the signal. I got fined Rs.100/- i.e about $2.5. He was looking for bribe, but I did not give him the opportunity to even talk about it. Had I bribed him I would have got away with paying him about half that and would not have had to wait for 20 min. But I just could not get myself to do that.

If you try that in Trinidad you might go to jail or you might get asked for more. Over here you have to feel out the policeman and then offer something and its going to be more than $ 20.
Personally I think its too risky. You just never know when you'll meet somebody who'll want to make a case against you.
In Trinidad, unless you know the cop, just pay the fine, its safer.

I have never bried a traffic cop with money, but I did use what my husband affectionately calls "emoional blackmail" to get a relaive of mine out of handcuffs, when the person drove on a suspended licence, with no car insuance.