Windows RT tablets could cost $500 to $700 -- too high to make them viable in a market filled with less expensive tablets, according to an IDC analyst who researched costs with device manufacturers and component suppliers.

"My biggest concern is that Windows RT tablets could be many times more expensive than the Amazon Fire price of $200 -- even something as high as $599 and above, which is a concern for their viability," said IDC analyst Tom Mainelli, in a telephone interview.