Oracle DBMS - Build A Better Case For Clustering By Analyzing Hardware Upgrade Costs
It's understandable that management may not want to invest in a lot of changes when it perceives that the window ain't broke. Unfortunately, this attitude may cause your organization to miss out on high availability and other advantages of a clustering solution, such as RAC.
One consideration that may make RAC more attractive to your business is if you look at machine upgrade costs over time. With a cluster, you may be able to stay up to the latest hardware standards by upgrading one or two boxes a year. Compare that with a mainframe solution where the cost of upgrading happens all at once. Showing the benefits for the hardware budget can sweeten the case for clustering.