You can't compare cost of chips / GH to cost of finished miners / GH. There is a lot more that goes into a finished miner than just the chips themselves. Remember if someone is selling products to consumers that includes the chips, PCBs, boxes with a thermal solution, is paying their employees and for space, production, overhead, etc. How much more does a computer cost than just it's CPU? Same thing here basically.
And theoretically our costs are lower because we aren't dealing with the major supply chain and logistics that go into assembling, selling and shipping to the consumer as volumes continue to increase. It's all about margin, which should be healthy selling chips, which coincidentally is where ASICMINER has the cost advantages.