I would not recommend u to exchange your flat or real money for bitcoin. It's too risky. Better just sped some minutes of your free time with commenting and getting bitcoins for that. After u pass newbi rank u may join some campaign that will pay u 
Do you just said commenting is also one of the way to collect btc? How is that possible?
Yes, for commenting you can earn BTC from signatures campaings - as Member you can join for example here:
https://bitcointalk.org/index.php?topic=1273144.0;topicseen
You can also earn by posting on other forums - for example here:
https://bitcointalk.org/index.php?topic=1448485.0