The barriers inhibiting more consumers from buying an iPhone seem to be crumbling, according to the latest findings from the NPD Group.

The report reveals that when it comes to the primary reasons consumers do not want to purchase an iPhone, "high price" was the second-leading reason -- 42 percent -- after "lack of interest" -- 55 percent. The iPhone 3G's original price of $199 set a smartphone benchmark, and halving that price to $99 while adding more features should significantly expand the market for Apple's smartphone, according to NPD.

"There is still a significant base of consumers who want the iPhone but have not switched, even though before the launch of the Palm Pre only seven percent of consumers felt that their carrier has a phone as good as, if not better than, the iPhone," said Ross Rubin, director of industry analysis of consumer technology for the NPD Group, New York.

The NPD Group specializes in wireless industry market research, including consumer and retail information. Its clients include more than 1,700 manufacturers, retailers and service companies.

Based on consumer tracking information reported in NPD's "iPhone Opportunity and Demand" report, one in five mobile phone owners say they want to purchase an iPhone, but have not yet done so.

According to NPD's report, data plan pricing and exclusivity remain key obstacles for iPhone adoption.

When it comes to their reasons for not purchasing an iPhone, 18 percent of consumers who have not purchased an iPhone cited the expense of the data plan, while 21 percent said they didn't want to switch carriers.

Many potential iPhone buyers are looking past lower device prices to recognize the greater expense of a two-year monthly data plan commitment.

"Key attributes attracting consumers to the iPhone include the touchscreen, the design and the Apple brand, and compatibility with accessories was more of a factor with women," Mr. Rubin said. "Among consumers who want an iPhone, expense was one of the leading reasons they have not gotten an iPhone, in addition to the need to switch carriers and the price of a data plan."

Voice-only plans from prepaid providers are very competitive with what the big four U.S. carriesr are offering. MetroPCS and Boost Mobile are offering unlimited voice or text plans in the range of $40 or $50 a month.

"The $99 price point for the iPhone does address some of the concerns consumers have about the device price, but in grand scheme of a two-year contract, there is not a tremendous factor in terms of reduced spending during that period, but only about one in five consumers seem to be doing that math," Mr. Rubin said.

"All carriers have inclusive data plans, but one of the marketing tactics that Sprint has taken against AT&T and the iPhone is to point out how consumers would save money over the course of a two-year contract with Sprint for the Pre," he said.

While an inclusive data plan with AT&T starts at around $100, extra features you can add on to that total, as iPhone users might pay for content or applications from the App Store or services from a third-party company.

Apple has introduced subscriptions in iPhone 3.0 operating system.

Information in NPD's "iPhone Opportunity and Demand -- A Consumer Perspective" report is based on an online survey of a nationally representative sample of 1,579 U.S. adults.

Results are projected to represent the entire population of Internet-using adult consumers. Sales figures do not include corporate/enterprise mobile phone sales.

"The iPhone has been a very successful device for AT&T, it has helped selling data plans, and it has been the most successful phone in U.S. cellular industry in terms of attracting customers from other carriers," Mr. Rubin said. "AT&T does offer a wide array of smartphones in addition to the iPhone.

"It seems unlikely that Verizon would get the iPhone before it had a significant national U.S. footprint of LTE, which likely won't happen for two or three years," he said. "Apple not interested in developing a CDMA iPhone."

Customers of other carriers, particularly Verizon Wireless, are unwilling to make the perceived compromises that might come with switching to AT&T, according to NPD.

"Verizon subscribers were disproportionately more concerned about switching from Verizon than those of other carriers," Mr. Rubin said. "They are less willing to switch."