The prices can vary depending on the services you are looking for and if there is a management layer on top of it.
I'd start off by shopping around not for the best price but rather the host who understands the needs of your application and can meet those with levels of guarantee behind their SLA.
Take a look at managed hosting, cloud computing and more specific 'Hybrid Cloud' which sounds like what you may be looking for. Something flexible, scalable and the ability to outsource the managed hosting portion of this.
If you need some help, drop me a message i'd be more than happy to help out.