For those who give cost per person as a gift, what if you have to travel a considerable distance to the event? Or if you have to book accommodation or a babysitter? Do you take those costs into consideration?
Good question. For us, we try to give the best we can afford to the married couple. If they feel we are important enough to them to include us in their special day, we try and return the feeling.

So in line with that, if we have to travel a long distance for the wedding, obviously our budget would be a bit different. We travelled to a wedding in Italy for one of dh's best friends. We couldn't afford to give them the same as if the wedding was local. We gave what we could.

As far as the cph thing, I certainly don't know how much each venue costs etc, so it's a guess on what we'd be costing them and then easing it.