Agree that it sounds like it is almost certainly the crossover pipe.
Do a search here and you will see that they are very prone to issues. IMO, they should be considered a wear item and replaced on a schedule of roughly every 50K miles regardless of whether their is a current issue or not.
It is not actually a hose, if that helps with your warranty situation. It a hard plastic pipe. There is one at the front of the engine, and another at the rear.
$2,000 to pull the intake is flat out nuts. It's 14 bolts IIRC, unhook the throttle body, and lift. For $2,000 I would be expecting a new water pump and new front/rear crossover pipes. If you are mechanically inclined at all, it is not a difficult job. You don't say how many miles you have, but if it is over 50K I would do the waterpump and both pipes and worry about it again in another 50K.