Insurance companies make money hand over fist. I can't imagine we can't do the same with the goal of just paying administration costs.
I think your biggest problem will be avoiding the rate/risk spiral and keeping the rates low enough that honest people with low-risk transactions are willing to use it. The more the rates go up, the higher the risk that will be needed to justify buying the insirance, which will lead to the rates going up again as all the insured transactions are high risk.
You need to find a way to force diligence on the part of at least one party.