In theory, one can purchase German rail passes online from bahn.de, and the price at the time of this posting was about $100 less than raileurope.com. My experience was that I tried three times to buy from bahn.de, but the transaction was rejected each time by Chase, even though I called every time and they assured me that they had authorized the transaction, "please try again". Each time I either filled out the online form or contacted bahn.de via phone, it would take a few days before they tried to charge the credit card.
While trying to contact the bahn.de folks to ask them to try my credit card again, I discovered that my verizon phone with international calling plan was unable to call either the bahn.de international ticket office in the UK or the main ticket office in Germany. Got an error about "calling restrictions", despite several calls to verizon. Ended up buying Skype credit and making the call that way. The bahn.de website lists a US-based number, but I only got voice mail "the google subscriber is not available, please leave a message".
Pretty annoyed with my chase visa card. I finally ended up buying my train passes through raileurope.com.