The Rackspace instance you are referencing has 4 vCPUs in it - the m1.large on Amazon has 2. Also, don't forget the prepay amounts on EC2 reserved instances in

The Rackspace instance you are referencing has 4 vCPUs in it - the m1.large on Amazon has 2. Also, don't forget the prepay amounts on EC2 reserved instances in your calculations! The prepay for 1 year on the m1.large is $243, making a reserved m1.large $1434 a year (365 days * 24 hours * $0.136/hour + $243).