I've been approached 3 times in the game to trade one of my knives for a spell. My problem is that, first, they asked for my Fine Hunting knife (the best I had at the time) and now they are asking me for Masterwork knives, virtually one-of-a-kind items!! (at least in my limited experience)
Couldn't they ask me to bring them some Fine Pawboard traps, or to fabricate some leather armor, or something, instead? I'm not going to trade an extremely rare item for a spell of limited value that I'd rarely use anyway.