I know this thread's old, but here's my personal experience with a CyberPower that I bought from Best Buy about a year and a half ago...
September 2016. I just drove clear across town to the far west side Best Buy, because neither the east side nor near-west stores had it. My heart was racing, I was so excited that I finally had a gaming PC. Hooked it up, fired it up, connected to the internet... "Windows is not genuine". As it turns out, this was actually a refurbished Windows 7 machine upgraded to Windows 10, and never activated (thank god it had a new W10 COA). It said absolutely NOTHING about being a refurb on the packaging, in store, or on the BB website. I solved the Activation issue, which wasn't too serious.
About a month down the road, it starts crashing. Dying and rebooting, usually without a BSOD or any sign of suspicious behavior. The original motherboard (more on that later...) was faulty right out of the box.
This motherboard was from 2012. The CPU was from 2012. The GPU was from 2012 (parts that were mid-range even then). In a computer that was being sold as "new" in 2016. Of course, the specific specs weren't listed anywhere, so what I was buying was a complete mystery. But it was cheap (RED FLAG).
The original PSU was just barely enough to power what was in there. The GPU was the first part I upgraded, around Christmastime that year. Of course, a new PSU had to come with it (I would upgrade the GPU again later).
Some connections, including some case lights, buttons, etc., were disconnected out-of-the-box, and after only about a year and a half of ownership, some of the case lights are already starting to fail.
Finally, after totally gutting the system and installing new MoBo, CPU, GPU, RAM, PSU, and an SSD, I'm finally having a great experience with this system. I've read reviews about CyberpowerPC online after buying the system. It sounds like their quality is very hit-and-miss. Some people really enjoy their systems. Others, me included, have been having nothing but trouble with theirs, usually to the tune of faulty and/or outdated hardware, low build quality, and bad customer service and tech support.
TL;DR: Cyberpower's systems use cheap, lower-end parts (unless you're willing to spend a small fortune), and their quality can be very hit-and-miss. Research, research, research. And if you do go to Best Buy, ask questions. Ask if it's new or "new". Read reviews on both the company and the system you're considering. Ask around on sites like TomsHardware.
Matt