You can run media from a potato. This will be at least 5x the cost of a cheap mini-PC. And you can't forget power draw. The Steam Machine has a 30W CPU, and I'd guess about 60W RAM which would add up to something like $120+ annually where a mini PC would cost closer to $7. 5 years later and the Steam Machine has eaten it's cost in power. Assuming it costs $500 like most consoles, you are looking at a total 5-year cost of $1100 where a mini-PC would be $100–200.