It really just depends on how you personally value the pets!
I would only trade 1-2 sorbets for the eat me, some people might be willing to overpay more or less. I haven't seen it going for more than a non so I wouldn't take it if I were you!
Keep in mind that this is all based on how I personally value it and how I see people valuing it, that doesn't mean that the eat me is worth this or that you can only get one paying that. I got my set trading for their list value and both sides of the trade were happy with the trade, there are lots of people here and not everyone will value the pets the same way!