Just posting a poorly formulated idea…
I recently started looking for a good offer for a variety of insurances other than the relatively transparent health insurances (i.e. life, invalidity daily allowance, private invalidity pension, and alike). The problem with most of them is that the insurance companies do not provide any interface to select insurance benefits to calculate the costs of an insurance (even though they have it anyway in-house). To find a good offer, a customer would have to meet around 10 different insurance agents, wait for their offers and compare them. That’s obviously quite a large effort and I guess hardly anyone does it (and thus ends up with a bad offer). So - wouldn’t it be an option to gather data from existing contracts and design such a calculator based on these data?
(I’m aware that it might be quite difficult to get enough customers sharing their contract data - and no possibility to earn money if one is transparent… but that’s why I would see it as an open-data project.)