An Apple iPhone is much cheaper to build than a HTC Thunderbolt, according to a recent smartphone teardown report by iSuppli.

The report says the teardown of HTC Thunderbolt revealed the total bill of materials (BOM) to be $262, the highest amount that iSuppli has ever seen for a smartphone. In comparison, Verizon iPhone 4’s BOM is only $171.35.

The most expensive part of HTC Thunderbolt is the 4G LTE component, which costs $39.75, over 15% of the total BOM.

The costly 4G LTE component puts the next generation of iPhone into a question – will it come with 4G LTE or not? If the new component costs around $40 and Apple keeps the rest of the elements the same, it would be 23% more expensive than the current iPhone 4

“It remains to be seen whether the next Apple iPhone set for introduction in September will support 4G LTE,” reported Wayne Lam of iSuppli.

“However, if it does, two things are clear. First, the iPhone’s minuscule printed circuit board (PCB) will have to grow in size in order to support the first-generation LTE baseband processor as well as all the supporting chipset. Second, the next iPhone’s BOM value certainly will increase substantially compared to the iPhone 4 if LTE is implemented in the same manner as in the HTC Thunderbolt,” Lam said.

The BOM does not necessarily equate directly to the retail price, which is a good news for those who were hoping to get a hand on the HTC powerhouse.

According to information leaked to SlashGear, Verizon may be offering HTC Thunderbolt for free with a 2-year contract.