Dead Space is on sale for 70% off and FIFA Soccer 12 is on sale for 50% off as GameFly Store Specials for the Weekend.
According to this list both games should activate on Origin.
EDIT: Although Dead Space is on the above list, you might have to contact Origin support and they’ll add the game for you apparently.
You won’t be able to see the CD keys for the games through the client if that’s your plan. You need to log into your account and click on the order number on the purchase history page. Then you’ll be able to see the activation keys for your games. Also note that you have to add a credit card to your account before you can purchase a game.
BTW GameFly has a refer a friend thing. So if you sign up through my link you’ll get a free month and I get a free month. I think that’s with a paid account/trial though. Good in case you want to play their unlimited free pc play games.
Also there’s a possibility Amazon will pricematch the deals in case you can’t buy it on GameFly and use a fake address.