I had paid about 20.00 for 1000 wow gold using AvatarForce.
They sent me an email and said since I used an unlisted phone number that they would need some other way to verify my i.d.
I am in the military and never got a *.mil email, so I couldnt do that. I move around alot so I didn't have a "listed" landline for them. And I don't have a scanner so I couldnt send them a picture of my i.d.
Apparently just paying them is insufficient. I don't know. Anyway, they refunded the full amount and life goes on, but man I am annoyed.  

 
This site is the cheapest legitimate site where you can buy currency for Guild Wars. Their 24/7 live support actually works and service is prompt provided they have stock. If not, the wait time is supposed to be 24-48 hours. I went through three other sites all of which were considerably cheaper before making a purchase with them.

All of those places were among the cheapest, but a total waste of time. Many Asian-based sites have piss poor communication/service or are just a plain scam. This company is based in the US. Luckily I will be getting refunds for those mistakes, but if you want to save yourself alot of time and frustration just buy from a legitimate seller like Avatarforce the first time.