So, you're selling codes to a fishy site using an autobuy platform while all your reviews are given by newbie accounts with 0 trust and allmost 0 history.
What could possibly go wrong
In case somebody is missing the obvious sarcasm: you could get scammed at the autobuy platform, OR the OP could go for a double whammy and let you pay to receive an invite to a site that was setup to scam people...
There is no way a malicious user is going to sell you "dirty" BTC for 30-50% off, he'll just run it trough a couple mixers/coinjoins/exchange for XMR/hotwallets him/herself and only lose 5-10% instead.
For everybody reading this topic: if something looks to good to be true, it usually is... Don't get scammed...
but at the moment it works and I can buy bitcoin cheaper .
this is the most important thing for me
I don't believe you purchased an "invite", have an account on this site or purchased any "dirty" bitcoin... I do believe that you're either the owner of this site, or a shill that's being payed to promote this site.
Why else would you create an account on this forum and make your very first post a post dedicated to criticizing the first non-shill that spoke up in this thread.
But what i believe isn't even relevant to this thread... It's about you (the owner) being able to proof you're a real service. And so far, you've shown that your service is "to good to be true, so it probably is", it's built on the pretense a hacker is smart enough to steal BTC but not smart enough to use a mixer, and you've clearly employed (or generated) a bunch of alts or shills to continuously bump your thread and make it look like a real business.
All these things are big, shiny, red flags...