Simple Google search will reveal various sources quoting costs at either $56 (parts only) or $150 (manufacturing). Even if it would be indeed "only" $56 for parts, then you need to account for R&D, assembly, testing, packaging, worldwide delivery, marketing, not-so-small retailer's margin, import duty and VAT (where applies) and I'm pretty sure it would sum-up nicely to sub-$150.

Also, this is something that I consider "common knowledge" and I cannot point you to any sources, but for years console makers (Microsoft, Sony & Nintendo) has been selling consoles for (or even below) the manufacturing costs to allow for wider adoption.

From what I recall, Microsoft in the beginning was breaking-even after they sold at least 3 games for given console. That's why piracy is so big problem in the console world, not only is the console maker not making money, but they are actually losing money on pirates that only buy console.