Is the price per person affected by searching a flight for more than one person?

The main case where the price-per-person will be different when searching for more than one person is when there is only one seat left at the cheapest fare. In such a case, the search engine (or at least every one I've ever seen) will search for the cheapest fare where all passengers can travel at the same fare. That might mean bumping all passengers to business class, or taking an entirely different route.

For sufficiently large groups, you might be eligible for a group discount, too, but I think you won't find those discounts on most online search engines. You'd likely need to go through a travel agent.

My experience confirms Flimzy answer, so I won't repeat that.

I would like to add a suggestion to get a cheaper price per person: when such situations arise just buy tickets separately and then share the total equally between each person. Try to find out which is the number of available tickets at the lowest fare and buy them in one transaction, then buy the others at higher fare. For example Ryanair website tells you how many seats are available with a given fare.

If you are quick enough (and maybe have 2 credit cards at hand) you can save some money.
I've personally used this trick a few times :-) but cannot guarantee that it will always work.

I can confirm one scenario where it makes difference - when you travel with kids. We used it this summer when travelling to Europe and it knocked off around $200 for the kids tickets. But not all airlines do it. But if you search e.g. on Kayak, there is under dropdown next to Search button this list of options:

• Adults 18-64
• Seniors 65+
• Youth 12-17
• Child 2-11
• Seat Infant under 2
• Lap Infant under 2

You can specify number of passengers for each age group and and then the price that Kayak shows is average price per passenger (so e.g. when price per adult only is $1400, with kids Kayak will start show $1300 per passenger) - and it also allows you to sort by it.

It does change. Airlines sell tickets in blocks, so lets say one block cost $300 per ticket and next block is $400 per ticket.

Assume you want to buy 2 ticket but there is only one left in $300 block then you will be paying a total of $700 as the second one will be priced at $400 - meaning $350 per ticket!