Where can I buy some coins with the cheapest price? Too many exchanger & trading sites out there, you don't know which is the best one.
The best way is to go to some meet ups with your friend or a trusted stranger and then buy it , buy it at the lowest value. That is called the p2p or the person to person trading , my friend do this and it help him and now he's sharing it to me.
Beware of dealing p2p trades in certain countries. In the US, for example, there are regualar cases when authorities were involved in such trades and ceased sellers claiming several violations of laws.