I buy and sell used hardware and sometimes I build salvage systems. There is not a lot of profit in it but it's fun. With computers I spend most of my time overclocking, troubleshooting problems, and filing RMA's.
I delidded the 7700k and sold it, I also delidded a 6700k I had but I sold that too. The 6700k was good for 4.7ghz at less than 1.4v.
The builds in my completed build list are old and have been upgraded.