Keep in mind the relatively low overall margins of the MMO space. Considering the cost of live team support, bandwidth, co-location facilities, game masters, customer service/account management, SG&A, and the ubiquitous credit card fees involved with recurring billing, the net profit is around 10-15%. This would generate around $2.25 per account in billing each month, $1.125mm net.
Assuming initial retail net of $25 per box after and a generous lifetime estimate of 3mm sell through for $75mm, the monthly net per account in billing would roll up $13.5mm at 500k subs. If the budget estimates of $300mm are anywhere near accurate, it would take SWTOR over 3 years just to break even at that level.