Apple may be able to build a cut-rate iPhone for $144, which would let it price the device between $299 and $349, hundreds less than the unsubsidized price tag of its flagship smartphone, an analyst said today. A lower-cost iPhone would be a major strategic shift by Apple, which has rigorously held the price line, and may signal that it believes real growth will be found only in emerging markets, said Sameer Singh, who covers the mobile industry at his Tech-Thoughts blog. “I think the primary driver would be their position in emerging markets,” said Singh in a Thursday email reply to questions. In a Jan. 14 post, Singh assembled a rough estimate of what it might cost Apple to assemble a lower-priced iPhone. His total, including manufacturing costs, came to $144.03.