Turn off javascript before clicking the link!
After seeing ybad's Battlefield 3 post today, I noticed that the workaround works for the entire Origin Store. Some games are on sale at the moment and I've bought a few with no issues. All you have to do is disable Javascript in your browser. This can be found in your browser settings or Google 'noscript extension'. I have only tested paying with PayPal. You should enter a US address (here's a classic: 1 Infinite Loop Cupertino, CA 95014)
Noteworthy mentions:
[Game Name - US$ (AU$)]
Battlefield 3 - $5 ($5.40)
Battlefield Bad Company 2 - $6 ($6.50)
Burnout Paradise Ultimate - $6 ($6.50)
Command & Conquer 3 - $6 ($6.50)
Command & Conquer 4 - $8 ($8.70)
Crysis - $6 ($6.50)
Crysis Warhead - $6 ($6.50)
Dead Space 2 - $6 ($6.50)
Dragon Age Origins - $8 ($8.70)
FIFA 12 - $6 ($6.50)
Mass Effect - $6 ($6.50)
Mass Effect 2 - $8 ($8.70)
Mirror's Edge - $6 ($6.50)
NFS Hot Pursuit - $6 ($6.50)
NFS Shift 2 Unleashed - $6 ($6.50)
NFS The Run - $6 ($6.50)
Also works on pre-orders, one of the more ridiculous examples was $39.99 for FIFA 14 as opposed to $69.99 in the local Origin Store.
Hope you enjoy this as much as I did.
edit: put list in alphabetical order
Nevermind, misread, thought with the workaround that could get any game 50% off :P