Plugging in numbers for my $1000 synology, which runs a half dozen dockers, a vm, and is off-site backed up (for $120/yr), it tells me that I’ll pay $135/month to run comparable kubernetes at google.
Even if you pretend my $75/month broadband connection is only used by the synology, and include power costs, the synology still wins by $10’s/month.
(I included 3TB of storage for kubernetes, and 6TB usable for synology, with 3TB used, and sized for the high-memory 4 core machine, since dram is the synology bottleneck, even with a low wattage cpu. The synology is intentionally over-sized and is basically idle, so “but scalability!” isn’t a valid complaint.)
Also, the 9’s I’ve observed were trouncing amazon for a while, though they may be catching up, thanks to comcast...
But if you want to roll your own, then you can, it's FOSS after all. kubeadm works very well.
Comparing Synology with anything Google is silly, but useful. You can rent dedicated machines easily. Leaseweb is nice. And then you can build your infrastructure for cheaper.
Yes, different things are different levels of complexity, and using a managed service means paying someone else to handle it.