It's my understanding that you shouldn't run into trouble if you use the region free codes. Having to use VPNs to bypass region restrictions -- which is a requirement for some of the codes that this site sells -- can potentially get your Steam account banned, so please exercise caution.
How did you get Sleeping Dogs for less than twenty bucks!?!
I haven't purchased any Origin keys at this point, and considering their product mix, I'm not likely to anytime soon. Maybe Medal of Honor: Warfighter will stir me to action? Are there any grey market sites that you can recommend?