Yeah, I've been through this before with GMG, with PayPal not working when their having a great sale. It seems to be working now though, as I was able to purchase Spec Ops, but I know what a bummer this is. Therefore if anyone wants to get Spec Ops but is unable to, you can PM me and I will purchase the game and PM the Steam code to you in exchange for $6 PayPal.
Just a few things though; first of all as I am currently overseas PayPal might charge a small fee, which must be absorbed by you in addition to any other fees. Also, there are no guarantees; if it doesn't work this time around then there's nothing I can do. And finally as the deal ends in 1 hr, I will only be purchasing for those who PM me in the next 45 min. Please guys, don't make me regret doing this.
Edit: After looking around a bit, it seems that GMG doesn't allow purchasing multiple copies of the same game, and since I've already purchased Spec Ops, I will be unable to purchase it for anyone else. Sorry.