If you are colocating in a data center you can only use 80% of your power circuits capacity. For example you can only use 16 amps out of a 20 amp circuit. So if you are running servers with dual power supplies most server brands will split the load across both power supplies. In this scenario you can only load down both circuits to 40% so if you do have a failover the live circuit will only be at 80% capacity and you will not have to worry about popping the circuit breaker.
The going price at most data centers for a 110v 20amp is $300 with ups and generator backup. For 208v 20amp the price would be $600. For a redundant B circuit 110v 20amp is going to be half $150 and $300 for 208. I highly recommend switchable PDU's. This will allow you to power cycle you equipment remotely and most of the better models will meter the power so you can know what your usage is. You can find a good quality remote manageable PDU for $350 to $800.