At this level, and all things being equal, it deals with the profit each insurance company needs/wants to make. If an insurance company is running lean and mean, then, they can provide the same coverage at a reduced cost. If this is not the case, it is a waste of time crossing state lines looking for a better price for ins.This is partly true, I believe. One thing that really drives up the cost of insurance are health care mandates by the state, ie. you must have X level of coverage and it must include these features. The insurance companies can't even control their own product. No, not health care, but the coverage provided by the insurance plan. That is dictated to them. So it doesn't matter whether person A in California can buy insurance from company XYZ in New York, if company XYZ must provide the exact same plan as every other company in California.