Your statement is contradictory for one reason. "The low cost of PC components", as you have mentioned, means "the low cost of RAM, cores, and disk space". These three things, add up to one powerful machine that can host dozens of VMs that do whatever you want them to do. I just built a custom PC from newegg, and with 32GB of ram, 6 cores, and TBs of storage (for cheap!), I can run more VMs than I could ever possibly need to, each with different OSs and purposes, and still never burden the underlying OS.
Cheap parts --> VMserver --> save space and electricity.