Well, as far as I'm concerned the rules already give me plenty of guidance for adjudicating a situation like that. That's one of the strengths of having a toolkit approach.4E's rules are designed to address questions likely to come up in play. The "use <random animal, summoned creature, or hapless hireling> to set off traps" tactic is one with a long and well-attested history in D&D, so it's not unreasonable to want at least some guidance from the book on how to handle it.
It's difficult to make money selling magic items when you have to pay full price to create them and can only sell them at 1/5th that price.You'll be eating those words when a PC sees the commercial possibilities in that spoon, corners the market, and builds a multi-million-gold-piece fake ice cream empire on magic spoons and gruel.