Gary wants to buy a PC for video editing. How much should he spend? Leo says that just about any PC can do video editing. The money comes from how much performance he'll want. Leo uses a Dell Precision Workstation with Xeon processors that scream. So they are very powerful and expensive. An iMac would be more than adequate, though, to capture and edit home movies. A MacBook Pro would also work.
Gary could also consider the Mac Mini. An i5 processor would work, but the i7 would be even better. Leo thinks the i9 would likely be overkill. 2.5 GHz to 3 GHz would be ideal. He should pay close attention to single core performance. Most programs aren't written to take advantage of multiple cores. For RAM, Gary should get 16GB. He'll also want an SSD that runs on the PCI-express bus. That'll give him the most bang for his buck in performance.
On the Windows side, Adobe Premiere Elements is a great video editor for under $100. You could sign up for Adobe Creative Cloud with Premiere Pro, but it's $50 a month.