Approaching the end game, allies become not very useful, as they are too weak compared to the main character. Moreover, "cheap" ones may be better than more expensive ones, since they can provide effects that are still useful compared to high combat stats.
I count sucking up a 5 point attack with a 2hp ally VERY useful, though I agree that cheap "disposable allies" are often better than expensive ones for just this reason. I can picture the scene in the tavern: "Hey, any of you noobs want to help me go after Maragath? I'll give you 2 gold pieces!"