A breakdown of the lowest-priced Apple Watch Sport (selling for $349) showed that it contains about $83.70 worth of parts. While that suggests that Apple's potential profit margin on its new smartwatch is more than 70 percent, the company has warned that estimates like this one done by IHS Suppli are rarely accurate. "There are cost breakdowns around our products that are much different than the reality," Apple CEO Tim Cook said in the analyst call after last week's earnings were announced for…