Disappointing article, ars is using desktop-vlass hardware to calculate the pricing, butthe steam machine is using laptop parts (CPU, GPU, and RAM).
This is an entry-level level PC, 700 is way too much, other entry-level miniPCs, which are between 500 and 600.
The linked reddit post (why couldn't he just link yo the original video content? ) does a much better job reasoning about the bill of materials and comparing it against other products