Probably more than most of you want to go through but I've found some good deals lately on Dispenser.tf
. It automates trades and most people use it to trade TF2 keys for games. Of course, this requires getting TF2 keys which you can either do via the Steam Market (and pay more or else wait forever for a good price) or off-site where you pay less but then have to go through buying keys via Paypal from some random guy.
Anyway, I bought some keys at the end of the Summer Sale when they were cheaper but also bought a couple for $2.30ish last night. I used the Steam Market because I have a bunch of GabeN Funbux and I'd rather take a hit using those than use real money just to save a few nickles.
I recently got Witcher 3 Pre-Order (MSRP $60 - paid $26 though I overpaid on that and saw better deals for ~$8 less... boo.), Fall of Cybertron (MSRP $60, paid $8.50) and Killing Floor Complete (MSRP $50, on sale for $12.75, paid $4.80). You do have to check for RU/CIS region locked versions and it's more hassle but after a terrible Summer Sale, I at least got some decent prices on stuff. There's also the remote chance of the seller doing a charge-back or something but the system uses Steam Rep to screen sellers. And you could possibly find better deals trading directly with people but I like the bot interface and not having to PM people, Steam chat, blah blah. Nice deal for the antisocial.
Edit: Also worth mentioning that while there's some good deals, most stuff is NOT a great deal unless you just have a surplus of cheap keys from somewhere. Best to just use the search function for games you're interested in and run the mental math (I just figure $2.40/key via market) to see if it's a deal. You can waste forever pawing through random sellers hoping to see something great just by chance. Edited, Jul 4th 2014 12:35pm by Jophiel