Well.. It depends on what you are doing. If indeed you are using majority of AWS services, then yeah, getting off these will be hard to impossible. But if all

Well.. It depends on what you are doing. If indeed you are using majority of AWS services, then yeah, getting off these will be hard to impossible. But if all you use is RDS, EC2 and S3 - it is quite easy to move to dedicated hardware once your service is up and running on AWS. Unless your load is not jumping around 10x all the time of course (then you will need dynamic scaling which is not quite possible with dedicated hardware)