What's the lowest cost router that will support a DS3, no need to channelize, all data.
The NM-1T3/E3 on a 2800 ISR will be lowest cost. But, that is without any services running on the router. If you are planning to run any services on the router along with line rate DS3, I would look at the 3845. This chassis gives you Full-rate T3/E3 with concurrent services. Example, QoS, ACL, Security Features, etc. Please refer the below URL for details.
*Pls rate if it helps*