Last year I built myself a "new" old but upgraded computer, based on the one I had for over 10 years
. Bits bought mostly on eBay or Amazon if new.
Gigabyte GA-X58-USB3 to GA-X58A-UD5 motherboard
Intel i7 950 to i7 980x (the 990x is still too expensive) CPU
12gb Ram to 24 Gb of faster Ram
Nvidia Quadro K2000 to K4200 graphic card
1TB Hard drive to 2TB SSD
The strategy was to have the old one available while I got the "new" one up and running and to subsequently have a backup with all my old files and software, ready to run just incase.
As the hardware was essentially the same, I figured that a clone of my existing hard drive to the new SSD would work. And it did
. I used a two bay docking station with a clone facility to do this.