If each of the types of cables is probably less than $5, how do you get a $70 price tag for the combined all-capabilities cable? I'd be surprised if it would cost more than $10.
Because that's how American brick-and-mortar retailers make their profit: they take a cable that you can buy on Ebay for $5 and mark it up to $50, while keeping their prices on big-ticket items (like a TV or laptop) somewhat competitive because people price-shop on those things, but not on accessories.
Have you seen the prices for VGA cables, cat5, etc. at Walmart, best buy, etc.? They absolutely will jack the price up because they know the only people who buy that stuff there are ignorant or too desperate to wait for shipping.
Brick-and-mortar prices are constrained from the top by competitive pressure too. They won't be selling full-capacity USB cables with 10x markup, because they'd lose even more business to on-line stores.
