We have accepted an invitation to the wedding and reception of a man DH has known some years and is a mentor figure to in their special interest group. We have only met Btb once and I have only met Gtb twice. They have requested money in place of presents or a wedding list. Btf and gtb have lived together for some time and are in mid 30s, no children.
I have no idea how to work out what a suitable amount would be to give as a present. They intend putting the money towards their honeymoon. I think there will be more than 100 guests attending. What do you suggest?