Buying BTC from a forum member is stupidity, even if the member has high green rating of trust your money can corrupt the person into giving up his or her account, we have exchanges for buying and selling coins, they are lot safer
Exchanges require kyc. So that may not be a problem for you but it is for some of us. I would rather do it peer to peer like btc was designed.
There are exchanges that do not need KYC for trading like
CoinSwitch, Changelly Changenow etc., Also, it is safe to trade on a exchange. It takes time and lot of research to judge a member with whom you can trade.