Keep in mind that you will not get a status upgrade on an International flight if that flight is going to Europe or Israel. You'll only get a comp upgrade from your status if you're going to Canada or the Caribbean. If you are going across the pond, that will make a huge difference in what you end up doing. I can't speak to the fare for the lap child but I do know that several airlines do not allow OLCI for lap-children as they need to check the child's birth certificate to confirm they are of the proper age to BE a lap-child. Since this is a FAA regulation and not a US regulation, I'd expect they don't want you showing up at the gate with a home-printed boarding pass and a 3-year-old who has no seat.