Bought a copy of SimCity for $59.99 when it came out, thought it was a great deal. Played it for a while, forgot about it. Tried to play again today, found out my Origin account had been disabled and that these guys just sell keys they get from either keygens or bought with stolen credit cards or paypal accounts. The lowest of the low IMO.
Trying to get a refund but I don't like my chances!
P.S. wish I had seen the later parts of this thread before I bought - http://forums.whirlpool.net.au/archive/1405626
Games come with a RRP and every legitimate vendor sells around those prices unless there is a one-off sale. You need a damn good reason and a very good reputation as a publisher to slash prices on brand new release titles. So if Google can't find you a price around the ones those CDKey websites offer, then 100% sure those keys are bought via stolen credit cards and accounts.
The only other way around is region restricted content. And then you might face the problem of the key not activating for your region or DLC incompatibility or no support from the developer/publisher.
Its a lucrative business btw. Steal a credit card, can't get something for yourself because you have higher chances of getting caught. So buy stuff with it and re-sell it. The money you make, even though is a fraction of the amount you spent on the stolen card, is white money for you.
<I am associated with the gaming industry for 10 years now>