I'm a noob at being scammed. Where can I report?

First of all, reddit does have flair for rep. Secondly, this is a key scam which is not investigated by Steamrep and Steam will not doing anything about it. I believe the most you can do is to attempt to find his steamtrades and/or reddit profile (if they exist) and leave negative rep. For reddit, keep chat log open, take as many screenshots as possible.

....why did you go first? He had no rep to speak of.

never go first

A noob at being scammed? well, don't worry, you'll get better at it eventually.

Wait ...

Why did you give all your keys first? You could give one or two of them to him. Then he give the gift and at the end you give the rest of keys. I think there's nothing you can do. Sorry :(

sorry about that man, i use to do the same thing going first when it's keys : gift... (it's really bad when thats happens)... just a question,Cossacks? that game? or the complete one? seems a lots of games for that one..
PS: (sorry i'm still noob on trade games, not so sure about prices and those kind of thing)

Do you have Enhanced Steam installed? Based on the name you have in your chatlog, that user has 31 negatives on Steamtrades and is suspended. With Enhanced Steam, you can link directly back to their Steamtrades profile, to help thwart impersonators and scammers.

Do not trust profile reps. They are just fake. If you see someone saying give me +rep because of trade,DO not rep him in return. Report instead. Source from steamrep thread.

lol

Your own fault. Also - way too many game keys for the game you asked for. And since these were Origin keys Steam won't do anything. Didn't happen in trade window so they don't care. Also, no calling out people.

And yes, he should've gone first with his game since it was tradable gift and his nickname didn't look very trustable either.

You've had a lot of people point out some of the obvious, but this entire problem could have been avoided if you had just done a small amount of of checking and asking the right questions.

• You had 1 major screwup I see in your chatlog that happened early in the convo and was poorly handled. You never ask how he found you. He says he doesn't use Steamtrades, but if thats the only place you have your ad up then you'd have immediately caught him in a lie. While you can browse and search Steamtrades without joining, you can't view a person's profile to get their Steam profile link.

• Enhanced Steam is an essential tool. It's good for anyone, but for traders its a necessity. This (my profile) is how the sidebar looks in Enhanced Steam. It's not going to protect you all of the time, but for you, you'd never have gotten ripped off considering this guy is a huge scammer (-31 on Steamtrades) and he has not bothered to try and hide himself.

• Rep on a Steam profile page means NOTHING. Yes, he very well could have had ten pages worth of good rep before he decided to thieve, but you can delete any comment made on your own profile. I'd bet some of those -31 left negative feedback on his profile, hes just able to delete it. If I had been in your position and he could not provide feedback from anywhere outside his Steam profile, I'd have immediately told him I wasnt going first. Just because someone has keys vs a gift doesn't mean shit if one party doesn't have at least some verifiable feedback. And, yes, Reddit has the Flair system as has been mentioned. Look here. If you hover over a persons SN on any of the posted threads, you'll see (20+ trades) etc. Click the name and it brings up detailed feedback. Basically EVERY trading site has some sort of feedback system. Even forum systems like CAG and Steam Forums trading subforum has a method of feedback.

As for reporting, I suggest you do it anywhere you can, Steam, SteamREP, and make a scammer warning post on ST (or find one as he probably has one there already lol). Report him here on SG as well. Pull up his profile here and use the report button for it. There's really not anywhere else I can think of off hand.

You're not going to get anything back for this and SteamREP probably will not mark him as a scammer, but again, hes probably already reported on SteamRep, look for a thread already about him and add to it. Even if nothing happens to him, you still need to report him wherreever you can just to help protect the rest of the community. The biggest issue with this is obviously you lost game keys and for another service no less. The one bright spot is this guy has been REALLY busy recently ripping people off, so contact some of them via the scammers feedback on ST and see if you guys can gang together and report him en masse. If a lot of people go to Steam about one person, they could do something.

Also, edit your Pastebin of his SN. Its considered calling out on SG and not allowed. Last thing you want after being ripped off is being suspended from here or ST, and yes, if you get suspended on SG, you're suspended on ST too.