1.) Us dollars. I'd liketo be around $2,500 but can go as high as $3,500
2. )United States
3.) Just the tower.
$2500 is actually excessive for just the tower to max this game...by pretty much double the cost of a system that would max this game out. But we'll get you some bells and whistles

CASE+PSU: http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.480379
MOBO+RAM: http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.468098
GPU+CPU: http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.444092
HDD: http://secure.newegg.com/Shopping/ShoppingCart.aspx?Submit=view
SOUNDCARD: http://www.newegg.com/Product/Product.aspx?Item=N82E16829102024
BLU-RAY Drive: http://www.newegg.com/Product/Product.aspx?Item=N82E16827136181
That'll run you about $1580 before ship/tax.
Some additions:
SSD: http://www.newegg.com/Product/Product.aspx?Item=N82E16820167024&cm_re=intel_ssd-_-20-167-024-_-Product...or get another Caviar Black HDD
DVD: http://www.newegg.com/Product/Product.aspx?Item=N82E16827135204&cm_re=asus_sata_dvd-_-27-135-204-_-Product
Alternatives:
GPU+CPU: http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.444093