If you are looking for short-term insurance for foreign visa holder, you may buy travel medical insurance, such as Patriot America.
If you are looking for long-term insurance, you may want to consider buying a regular domestic health insurance as the visitors' insurance does not meet the Obama Care requirements.
For more information: Health Insurance for H1B Visa Holders
Insurance rates are regulated by law. You can't find the same insurance plan for a lower price anywhere else