A retail price of $399 would give Microsoft a 23% margin, while $499 would produce a margin of 38%.

But profit margin, Singh argued, is not as critical to Microsoft as is its existing relationships with hardware partners, known as OEMs, for "original equipment manufactures" -- the Acers, Dells and Hewlett-Packards of the industry.

"Microsoft would be under considerable pressure to ensure that the Surface is priced in the same ballpark as tablets from OEM partners," Singh argued. "Unfortunately, OEMs are also at a cost disadvantage as they need to pay Microsoft a license fee of $50-$65 per Windows RT device."

With that license in the mix, Singh said the BOM of OEM tablets similar to the Surface RT would be in the $300-$350 range. To keep OEMs happy, Microsoft will have to price its tablet with enough room for OEMs to sell theirs at a profit: Thus his price range of $399-$499 for the Surface RT.

Microsoft said as much earlier this year, when it promised prices for the Surface RT would be "."