I just recieved an email from Green Man Gaming for 20% off of BF4.  This will bring the price of BF4 to $47.99 and the Premium Service to $39.99.  The email said that the offer will be good until the end of September.  

If you have bought anything form GMG before, and you are interested in pre-ordering BF4, you may want to check your email.

I don't know if this is a unique offer targeted to each email recipient, or if it will be available to all.  There was a discount code attached.  I will research a little more.  If it is not a unique, one-time-use code, I will post it up here later.

Edit: Not a unique code, so everyone is able to get in on this.  Use Code TAREM-NBAR4-GDF84

These guys offer great deals and coupon codes every week. British company and some US banks have issues with their transactions for some reason. I generally stick with PayPal when buying games from them.