I know that in the States, group policies sometimes do not have aviation clauses in them, so that relatively cheap policies can be had by joining some affiliated group, such as the Reserve Officer's Association or such. For annual dues of perhaps $25, the term policies can be bought at annual prices typically about $1 per $1000 or so.
The Experimental Aircraft Association ($40 annual dues) has a policy that allows flight in experimental aircraft and insurance up to 150,000 at about 3X times the above rate.
http://www.harveywatt.com/eaa/index.html