How to calculate the budget for a vacation with friends taking into account reduced prices through B-ID?

The four of us are planning a one-week vacation in the summer of 2027. The difficulty with the calculation is that two friends have a severely disabled ID without an accompanying person. This means that your costs for public transport or entrance fees are cheaper or free. We don't want to split the financial compensation between all four. The balance can and should stay with the two friends. But which template (in Excel or Google Sheets) or app do we use to calculate this easiest in the end? e.g