Hi, thanks for pointing this out! Two questions:
1. Do you think that inaccuracy undercuts the point? If so, I'll correct the article; if not, I'll include it as a note in my planned follow-up. 2. Do you have the link(s) handy for those figures? If not, I can try to find them myself, but I figured it would be easier to ask first.
If you Google you'll find links of varying quality. Direct statements from Sony, but Nintendo and Microsoft not so much. It's all third party analysis which I find compelling.
Does your analysis still hold if the Steam Box base model sells for $600? Analysts estimated the BOM at $425 - $450. Add a little bit for RAM inflation, and Valve can still sell for $600 and technically be selling without subsidies as promised. They also promised to price it "like a PC". Lots of PC's sell for $300, so that also doesn't really constrain them.
I don't think your analysis depends on the Steam Box selling for higher than $600, but you're a better judge of that than I am.