Cell phones are not sold below cost. You can only get them at a "below cost" price when buying them with a contract which is typically worth $1500+. It's simply deferred payment, not selling below cost. The key here is that paying the additional money later on is
not optional. They will charge you fees, hit your credit, send debt collectors after you, and could potentially sue you if you don't pay.
It's true for video game consoles, occasionally, but the consoles are not very useful without games, which they make plenty of money on. The overall average price paid by customers over the lifetime of their purchases is correlated fairly well with the cost of making the stuff. The same goes for razors, printers, and whatever else you care to find that follows this model.
In any case, these are the exception, not the rule. The price of things I normally buy, like food, clothes, gasoline, electricity, and yes, electronics, are strongly based on their costs.
Prestige brands can be sold well above cost precisely because luxury brands become less competitive. Cheap handbags are basically fungible, but luxury ones aren't. When people want an LuxuryCo handbag, they want that, not an equivalent knockoff brand.
When it comes to telecommunications, you can see this happen in competitive markets like hosting providers. The price you pay for a server is pretty strongly linked to the cost of running that server. Dialup ISPs followed the same curve, ultimately ending up with service that was basically free (often ad-supported) because it cost so little to provide, because dialup was a competitive market. Home broadband generally isn't in the US, resulting in prices which can substantially exceed the costs of running the service. In places with more competition, prices more closely match the costs.
To quote the All-Knowing Wikipedia:
"In perfect competition, any profit-maximizing producer faces a market price equal to its marginal cost (P=MC). This implies that a factor's price equals the factor's marginal revenue product."
http://en.wikipedia.org/wiki/Perfect_competition
Of course, you never get perfect competition in the real world, but that's just my point: to the extent that prices don't match costs, it's because competition isn't perfect. The less competitive a market, the less the correlation between prices and costs.