do i have to pay for it?
Yes, they typically charge a couple of percent.
If you want the coins for gambling (which is a bad idea in the first place, an addicting waste of time and money), it is probably not worth worrying about getting traced.
Coinbase would probably not press charges or take anything to court, as it is not unusual for people to use bitcoin for gambling.
If you gamble directly off Coinbase, they would just freeze your account, if you take the coins out first, they are out of their control.
I believe the reason why Coinbase bans gambling is because they cover transaction fees for withdrawal, and gambling websites usually cause a high transaction volume, which Coinbase would have to pay for if they let you gamble.
1. On this forum, if you get a response from someone that has an advertisement in the signature space of their post then there is an extremely good chance that they have no idea what they are talking about and are just making up a nonsense response to increase their post count. Most of them get paid per post, so they are more interested in creating posts than actually learning and helping. You've received 8 such responses in this thread so far and none of them have accurately answered your question.
OK, I did not know that blockchain.info let you have the keys, my bad, sorry about that.
The question referenced in your post did not exist at the time of my first post, did you expect me to predict it?
The importance of controlling your own keys is well known, as users of mtgox found out the hard way.
Finally, the part about using a mix is standard procedure for anonymization.
What part of my post is spam?
Or is my post the one exception that is not spam?
Please do not make sweeping statements about signatures implying spam.