Tech firms seem to have this uncanny ability to significantly boost functionality while significantly reducing cost with each new generation of a product -- and you'll never believe this, but it looks like Apple is no exception. The teardown and bean-counting experts over at iSuppli are at it again with the iPhone 3G, finding that the whole kit and kaboodle tallies up to just $174.33 (give or take) for the 8GB model in material and manufacturing costs. That works out to about $53 less than iSuppli's estimate for the original 8GB model back in June of last year, an amount saved in part by moving to a single 10-layer circuit board (versus a pair of 6-layer boards). The firm figures Apple's shelling out about $50 in royalties for each iPhone 3G that rolls off the assembly line, leading to a grand total of $224.33 in costs. Offset that with a healthy AT&T subsidy, and all told, we're looking at something like a 55 percent margin to help Steve finance his next round of black turtlenecks.