this is a scam forum where all vendors is runs by one member (forum administrator ) they use fake reviews and feedback too from fake accounts, such scam forums is very popular kind of scam now days . so take care .
What makes you think that someone sells 8k BTC for only 3.5 BTC !!! Anyone who have 0.0001 of logic will know it's a scam.
I do not believe there are people fail in this kind of scam.
I do not think that it do worth creating another telegram Group, because it will get deleted by telegram again sooner than later, telegram is no more like before since the arrest of its founder in France the last year, since then they start to delete bots / channel / Groups related to the darknet .