Insurance history is scattered with companies offering what appears to be great cover at low price. If someone is offering any product that seems cheaper than everyone else, for a lower price, what generally happens is that either the company goes under, or your chances of getting any claim paid are negligible. If it looks cheap and nasty, it usually is.
There are insurance providers outside the UK and the USA, who are reputable, but if you buy from any intermediary or insurer who is not covered by regulations within your own country, then you have no consumer protection at all.
There are insurers who claim to offer international insurances which are available for UK residents, and seem to offer cover for treatment in any country. Some of these companies have a poor track record and reputation within the insurance industry.
Some companies within the medical travel industry seem to offer travel and other insurances. Many of these do not understand the limitations of what they are offering. Several have been asked for clarification of what they offer- few reply.
For example, any company that sells insurance within the UK, even if it only uses one insurer and leaves the consumer and insurer to deal direct, must be authorised by the Financial Services Authority. There are some UK medical travel sites which appear to offer insurance but do not appear to be regulated.
If in doubt as to whether any UK insurer, intermediary or agency is regulated, ask what its FSA reference number is or check the FSA register at http://www.fsa.gov.uk/.
Some basic rules apply to all insurances;
Ensure any price is a quotation, not a rough indication.