The one thing I have to start planning at this point with 7 coming out later this year is gathering everything needed for new build. The present case ran about $1,200 by the time everything was added in including extra drives including a usb flash drive.
The external usb hard drive was found needed internally for testing space after already adding in a larger storage drive to boot! A new OS after 2yrs. means another build after almost that amount of time as well.