I am looking at purchasing a Berkshire Hathaway Travel Protection plan, as we may need to interrupt an upcoming trip to return early for a covered reason. I am looking for experienced input specifically regarding how to calculate our non-fundable cost amount for purchasing the policy. Their trip interruption policy covers up to 150% of the non-refundable insured cost.

The round trip ticket from US to UK is the biggest cost of the trip, which is about $15K. Once we start the trip (fly the first leg to get to UK), I wanted to confirm that we will not get anything of that $15K round trip cost refunded to us even if that $15K is included in the covered amount of non-refundable cost, will we (if this is even possible, how do they calculate what the unused portion of a RT ticket is)? If I cannot get any portion of the $15K RT ticket cost refunded, I'm wondering whether it should be included in the trip cost calculation at all?

If we need to change our RT to return earlier than planned, the cost is approximately $6K (this is not a change fee, but just the fare difference+tax). My understanding is that since this isn't yet pre-paid non-refundable cost, I cannot add this $6K to the trip cost calculation. Is this correct? If it is, then I'm wondering if we're forced to add the $15K RT ticket cost to the trip cost calculation in order to receive coverage for the additional $6K ticket cost? Please note: I have called them to ask these questions, but they haven't been very helpful, other than to keep telling me that I just need to total all non-refundable costs that need to be covered.

Thank you for your help in clarifying how I should be calculating the trip cost for this RT + additional return tickets for trip interruption insurance.