Originally Posted by
swag
Simple test, do a search for 2 passengers. If the price is more than double that for one person, then it's true. (At the moment, anyway).
In fact if there is only 1 seat left at a certain price (which really just means, only 1 inventory in that fare class) and you search for 2 passengers, you won't get lower price + higher price. You will get 2x higher price, because they will book both in the same fare class. The cheaper fare may still be available after you book the two expensive ones.