I am at a loss, how long does this really take? I mean I build systems all of the time, so for me I can build and cable a high end system (tidily) in less than 2 hours, that includes unpacking all the stuff. It takes a bit longer when you get people wanting 15 fans with several RGB/fan hubs. Getting the base Windows install and drivers take an hour, that is if you are re-installing, and then however long it takes you to get it back to how you want it.
As for parting something out, that probably takes longer due to procrastination and such that getting the stuff delivered. Split those hours over 2 years and even if it was a 10 hour total that is less than 1 minute per day... its hardly worth worrying about.