Fanatical (silly name imo) formerly known as Bundle Stars have taken a leaf out of Steams Sale bargains and are offering new Flash Deals every hour for the rest of today so it's worth having a gander every so often. https://www.fanatical.com/en/black-friday?
There's a couple of good deals so far but check Steam for current pricing as the Steam Autumn sale is now on and in the past I've noticed Bundlestars are offering bargains that are matched on Steam meaning you might as well cut out the middle man.
I got caught out like that a couple of months after Battlefield 4 released, I bought a Bf4 code for 8 quid from a key site but when I went to use it on Origin it was on sale there for 4 quid so I ended up buying it direct and giving the other key code away on Moddb.
Everything you want to know about Degtarev's zone is in the: COP Survival guidehttp://cop.zsg.dk/